Isolated single nerve fibers of the toad were excited by voltages increasing linearly at varying rates. It was concluded that a linearly increasing voltage is effective in evoking an electrical response in the fiber when it rises above the rheobasic voltage at a rate greater than the minimal gradient of the fiber. Electrical responses are evoked at short (and somewhat variable) time-intervals after the stimulating voltages have reached-the rheobasic voltage.

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(1) Isolated single nerve fibers of the toad were excited with exponentially rising voltages. It was shown that the relation between the final voltage V_i and the time-constant of voltage-rise RC is expressed by a good straight line. This experimental fact indicates that the rate of increase of the stimulating voltage dV (t)/dt shows a constant value at the moment when the voltage V (t) crosses the rheobasic voltage.
(2) The utilization-time and the latent period of action current were also determined. It was found that the action current of the nerve fiber is set up a few milliseconds after V (t) has crossed the rheobasic voltage at a rate greater than the minimal voltage gradient of the fiber. The utilization-time ended near the moment at which the action current of the fiber was set up.
(3) The effect of CaCl₂-excess and CaCl₂-deficiency and of electrotonus upon the V_i-RC relation was also investigated. Change in the content of CaCl₂ in Ringer changed the rheobase but not at once influenced the minimal gradient of the fiber. Catelectrotonus decreased and anelectrotonus increased the minimal gradient.

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The human retina was stimulated by a subthreshold electric shock, and the change in electrical excitability caused by this stimulus was investigated by another electrical stimulus delivered at varying intervals after cessation of the sensitizing stimulus. Stimulating electrodes were placed at the forehead and the occiput, the index of excitation being an electric phosphene.
1. The excitability-time curve shows a periodic course, the amplitude of oscillation decreasing exponentially.
2. The frequency of oscillation is 18 cycles per sec., and this agrees closely with the lowest optimum frequency of the retina as determined by stimulation with alternating currents.
3. More detailed study of this phenomenon revealed that some oscillations with higher frequencies are superimposed upon the fnndamental oscillation observed above. This finding corresponds to the fact that there appear three or more minima in the strength-frequency curve obtained in stimulation experiments with alternating currents.
4. Thus, the periodic excitability of the human retina can be demonstrated in the two ways, i. e. by the present method and by the method of resonance.

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1. In a moderately sweating condition pressure upon one side of the body evokes without exception a hemihidrosis of the opposite side.
2. In similar conditions, pressure upon the soles or hip evokes the upper and lower sweating reflex.
3. Pressure on one side of the body does influence sweating from mental origin.

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Further studies were made on the accelerating interaction between Lillie's nerve models from various aspects. The results obtained can be summarised as follows:
1. If two cores I and II are activated one after the other with a short interval in between, the activation wave in I makes the conduction velocity of the wave in II always larger than usual, as was previously ascertained, and that
a) The action is strengthened if many, instead of one, cores are activated simultaneously to cooperate together as accelerators, and
b) The action gets weakened, if a single accelerator has many cores to affect on, instead of one.
2. The intensity of the accelerating action depends on the distance between the cores, i.e., it is the stronger, the smaller the distance is
.3. The direction of the activation wave as an accelerator is insignificant.
4. The accelerating action lasts for a few minutes in general, the intensity being strongest directly after the sweep of the accelerating wave, then dropping acutely to a low value, and then getting weaker and weaker slowly with time.
We don't know yet whether such an accelerating action as observed in the model, does take place in nerve in situ or not. It is obvious, however, that all the results obtained are due to electric interaction, and we know, on the other hand, that there is, in nerve, the “action current, ” an electric event quite similar to the activation current in the model. We shall have to bear in mind, therefore, that there would sometimes occur an accelerating interaction between nerve fibres in situ, too, although it is not clear at all at present how strong it will be.

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The interaction between two Lillie's nerve models, was examined from two points of view. The results obtained are as follows.
1. The conductivity-enhancing action.
An activation wave of one core acts on a neighbouring core so as to make the distance travelled by a wave in the latter more or less larger than usual. The action gets stronger with larger immersion times at which the examinations are made. It seems that there is a certain critical immersion time, at which the distance travelled tends, practicaly to say, from finite to infinity.
2. The recovery-promoting action.
a). The refractory period estimated at a distant point, taking the arrival of an activation wave there as the indicator, is shortened by an activation wave sweeping along a neighbouring core.
b). A wave, which is incapable of passing through a refractory range of a core, becomes capable of it if helped by a previous activation of a neighbouring core.
Most of the examinations described in Parts I and II of this article were nothing but those directed on the action of an activated core upon a resting neighbour.
The actions revealed are of various, appearances, but essentially they point to just one thing, that is, in one word, an “excitatory” action in the broad sense of the word. This action is unquestionably based on the activation current flowing in and out of the activated core through the resting one. The current must alter the electro-chemical state of the “membrane” of the core in some or other way, and if judged from the result, the alteration aroused must be, after all, “anodic, ” which is exciting in the model. How such an alteration is left behind and how it is distributed along a core after a sweep of a wave in another core, is not so simple a question to be answered exactly, but it seems theoretically not improbable; either. We have, however, a more important question, that is, whether the same action takes place in living nerves, too, or not. If it does, it may serve much, together with the simultaneous interaction (Yamagiwa (7)), in making us understand the nervous functioning as a whole.

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1) Effects of alkali metal and alkaline earth metal ions upon the slopefactor and the intensity-factor in electric excitation of nerve were investigated. Fabre's “constante linéaire” (c. l.) was measured by an improved method. The ions studied were K, NH₄, Na, Ca and Mg. The isotonic solutions of their chloride were mixed with Ringer solution at various proportions, and changes in the c. l. and the rheobase V after the application were traced.
2) All the ions of the two groups, alkali metal and alkaline earth metalions, affect the c. l. of the nerve in substantially the same manner. At low concentrations they increase the c. L and at high they decrease it, and there exists a certain intermediate concentration, at which there is practically no change in the c. l. These two opposite effects are however, at every concentration, manifestations of the two different phases in the effect of the ions, namely the c. l.decreasing effect in the early phase and the c. l.-increasing effect in the later phase.
3) Between the alkali metal and alkaline earth metal ions there is a remarkable quantitative difference in the value of the intermediate concentration and in the relative intensities of the two different phases stated above. One may therefore speak of a quantitative antagonism between them.
4) The changes in the rheobase V and the threshold strength I for the saturation current run parallel with that in the c. l; they change their magnitudes in the same direction, the change in I being always more pronounced than that in V. This change in I (proportional to the “pente limite, ” i. e. the direct expression of the slope-factor) and in V (the intensity-factor) is a typical one brought about by the variation of environmental conditions of excitable tissues.

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The effects of choline and betaine on the regeneration of the visual purple were examined, employing frogs as the experimental animals.
The examinations were performed in two ways, namely, 1) simple comparisons of the retinal colours with Garten's table, and 2) the measurement of the visual purple concentration by means of a photoelectric spectrophotometer.
The results showed that choline and betaine were much stronger than pilocarpine in the augmentative effect on the visual purple regeneration.

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Having confirmed the augmentative effects of choline and betaine on the regeneration of the visual purple in previous experiments, the author studied the effects of creatine and creatinine, chemically, closely related to choline and betaine, and also sodium monoiodoacetate which plays as important role in the metabolism of creatine.
In the first series of experiments, the colours of the retinae isolated from the dark adapted animals to which some creatine, creatinine or monoiodoacetate had been previously injected, were examined by means of Garten's table and compared with those of the control animals. The results showed that the retinae taken from the test animals were paler in colour than those of the controls.
In the second series of experiments, the concentrations of the visual purple of test and control animals were measured and compared by means of a photoelectric spectrophotometer. The results showed that creatine, creatinine, and sodium monoiodoacetate inhibited the regeneration of the visual purple. The effects were found to be considerably stronger than that of cocaine.

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1. Electrical currents of varying configurations were applied to single nervefibers of the toad either through a micro-electrode placed directly on one of the nodes of the fiber or through a pair of large electrodes immersed in the poolsof Ringer on both sides of a bridge-insulator.
2. It was shown that the time course of the local excitatory state produced at the node by a brief shock depends markedly upon the mode of application of the shock to the fiber. A brief shock applied at a point far from a node was found to produce, at the node, an excitatory state which attains maximum after a considerable delay. A shock applied directly to a node was shown to induce an excitatory state which grows and decays faster than that caused by a shock applied to the node indirectly.
3. Considering that the action current led through the myelin sheath decays approximately exponentially with time constant of about 100 microseconds, propagation of the potential wave (electrotonic potential) was discussed. It was concluded that the local excitatory state is nothing but the potential difference across the surface membrane at the node of Ranvier, The importance of these results in the whole problem of electric excitation and impulse transmission in the tissues was emphasized.

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1. The lateral-line nerve of Japanese eel yields vigorous spontaneous dischargesas many other fishes do.
2. These spontaneous discharges are much influenced by temperature of the externalmilieu.
3. Each fiber of this nerve refers to a certain limited skin area of 7-10mm. in length along the lateral-line. This is a sensory unit.
4. The spike discharges of a single fiber of this nerve vary in size. Some arelarge and the others are small.
5. These spontaneous discharges occur quasi-periodically and the average frequency of small spikes is higher than-that of large spikes. In stimulation of the receptor, however, the frequency of the large spikes become much higher than that of small spikes. Naturally large spikes are elicited from thick fibers and small spikes from thin fibers.
6. The statistical treatment of the spike-intervals shows that most of these spike discharges occur at random, owing to the changes of the external as well as internal environments.
7. Some of these discharges have a relatively high correlation with the heartbeat.
8. Histologically the lateral-line organ of the fish shows, even in its fine structure, a marked similarity to the Corti's organ of the higher mammal.
9. The intimate relationship between the spontaneous discharges of the fibers of this nerve and the heart-beat is suggestive of the mechanism of the human ear-tinnitus.
10. A few thicker fibers and many thinner fibers innervate together a receptor, each innervating different groups of sensory cells respectively.
11. It seems probable that the thinner fibers are related to the threshold, that is, to the perception of stimuli, and thicker fibers to the discrimination of sensation.

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1) During the course of many investigations in this institute on the various problems in, physiology of stimulation with the slope-factor as the main theme, it has become evident that there exists an interesting relationship between the changes in various excitation attitudes of excitable tissue and those in the environmental conditions of the tissue. Certain attitudes always accompany certain other attitudes under certain environmental conditions, while attitudes other than the former ones accompany still different attitudes under different conditions, aid both the excitation attitudes of the excitable tissue and the environmental conditions can be classified into two groups mutually confronting each other (table1).
2) The relationship among the excitation attitudes appearing in company is treated in turn:λand the chronaxie, λand the intensity-factor (the rheobase and the threshold of make excitation), λand single or multiple responses. Chief observations related to them are cited, and the facts and their significance aredescribed.
3) Actions of various environmental conditions are considered: temperature, PH, osmotic, pressure, electrodes of electric polarization and ions. Manyinvestigations in this institute on these actions, which contributed to the formation of the classification, are presented.
4) Some experimental conditions, under which the excitation attitudes suffer changes in manners different from that stated above, are enumerated: the electrotonus and the relation of size between the electrode and the excited body. As they have an intimate relation with stimulation itself, they are called stimulative conditions, and it is considered that they can be treated as conditions of different kinds than the environmental conditions.

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Intraretinal action potential was successfully recorded by means of micropipetteinserted into the retina. The localization of the electrode in the retina could be determined by a characteristic potential change during the insertion of electrode. It was found that the shape of the action potential thus detected intraretinally differs remarkably according to the localization of the electrode, considerations on which have led to a belief, that P I and the resting potential originate in most certainty in the receptors layer, and that P III originates in bipolar cells layer. Reports on the nature of the negative potentials intraretinally detected and on P II localization were left to succeeding papers.

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1. A simple device sensitive enough to demonstrate the tonic neck reflex in healthy human subjects is described. It enables us to measure the magnitude of the reflex flexion or extension of the fore-arm at the elbow-joint.
2. The regularity of the reflex effect exactly follows the formulation of Magnus and de Kleijn.
3. Intensity of the tonic neck reflex is stronger in lower ages; it gradually diminishes as the age advances from juvenile to adult stage.
4. Enhancement of the reflex intensity was observed in cases of oxygen deficiency and lack of sleep.
5. Negative correlation between the intensity of the tonic neck reflex and the ability of quick repetitive movement was shown.

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1. The repetitive response of a nerve fiber was induced by applying constant currents to the nerve trunk or to a single nerve fiber treated with a 5 per cent NaCl solution.
2. The relation between the voltage of the applied current and the response time is represented by a curve of an ordinary hyperbolic shape, though the latter is comparatively longer than that of normal make response.
3. Particularly long intervals were often found between two successive impulses in a series of repetitive impulses, perhaps expressing conduction blocks.
4. The relation of the logarithm of the applied voltage to the frequency between impulses was approximately represented by a straight line.
5. The accommodation of the nerve fiber was decreased after application of a NaCl solution.
6. The recovery process of the nerve fiber was retarded by application of a NaCl solution. The parallel relation between the recovery curve and the frequency of the repetitive response suggests that the recovery process may determine the frequency of the repetitive response.

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1. Single thermo-junction of silver plated-constantan of extremely low heat capacity and heat conductivity has been constructed, which is capable of measuring ‘real’ skin temperature.
2. The chief advantages are: the exact measurement of skin temperature and the quick response of the system-one measurement can be done within several seconds.
3. The variability of skin temperature within a relatively small area, the fluctuation at a given point, and others have definitely been proved.

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Threshold determinations were made with low frequency A. Cs. on single nerve fiber preparations of the toad. The minimal gradient and the rheobase of the fiber was determined by stimulating the nerve fiber with exponentially increasing currents. The threshold voltage of the A. C. becomes higher, as the frequency becomes lower. The observed values were well in accordance with Hill-Tasaki's formula.

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1. There were found marked individual differences in the vascular reaction to cold reported by Lewis which protects the temperature fall of fingers or toes in severe cold. The difference should be an essential factor in constitutional difference of resistance against frost damage.
2. A method was devised to determine the temperature reaction to cold by dipping the middle finger of the subject in ice water for 30 minutes, and measuring its skin temperature, and to compare the reactivity of the subject with one another by evaluating the so-called. “resistance index of frost bite” from the temperature curve thus determined. The method was called “a point test of the resistance against frost bite”.
3. The resistance index estimated by the method was fairly reproducible, as far as the experimental conditions were constant. When measuring repeated attempts should, however, be avoided unless after several hours, and to have such living conditions before and during the measurement that do not cause changes in the thermoregulatory function.
4. A marked seasonal change was found in the temperature reaction of one and the same subject, which increased in summer, and decreased in winter. The change was found to be mainly due to the change of room temperature. Even at the same room temperature, however, the reaction differed a little in summer and winter, i. e. is accelerated in the former when compared with the latter. The difference is probably due to an acclimatization of the vasomotor centre, in which the tonus changes to dilation of the skin vessels of extremities in summer, and constriction in winter.
5. Influences of environmental temperature were examined in detail and it was found that the reactivity was accelerated by rise in room temperature in proportion with the magnitude of the reactivity itself. This fact can be explained by the fact that the reactivity of vessels is controlled by the tonus of the vasomotor, especially of the vasodilator, which changes with the environmental temperature.
6. Effects of humidity on the temperature reaction was proved to exist, but not so marked as those of room temperature.
7. Making use of the above experimental results, a method was devised to eliminate the errors in the temperature reaction due to the change of room temperature, and to evaluate the resistance index at the standard temperature of 20°C. from measurements at other temperatures. It was found that 81%-94% of values thus corrected coincided with those actually measured at 20°C. withinthe scope of experimental error, when the room temperature was between 15C°C. to 25°C.

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1. The contents of free and bound creatine in the extracts of light and dark adapted retinae of toads were estimated by means of Jaffe's reaction and of a photoelectric spectrophotometer.
2. The total amounts of free creatine in the extract of 40 retinae illuminated and dark adapted were 73γ and 56γ respectively while the amounts of creatine originating from the phosphocreatine in the same extract were 7γ and γ respectively.
3. These results together with the previous observation on the inhibitory effects of creatine on the regeneration of visual purple, lead us to conclude that the breakdown and resynthesis of phosphocreatine are directly related with the photochemical changes of the visual purple.

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The effects of methionine, cysteine and cystine on the regeneration of the visual purple were examined. Fresh toads were used as the test animals.
In the first series of experiments, the retinae were isolated from the dark adapted animals to which methionine, cystine or cysteine, were injected previously, and their colours were compared with these of the control animals by means of Garten's table.
In the second series of experiments, the concentration of the visual purple of the premedicated and the control animals were measured by a photoelectric spectrophotometer.
It was recognized that methionine augmented the regeneration of the visual purple, but that cysteine and cystine inhibited it.

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The respiration of frog retinae with or without the pigmented epithelium, in dark or light adapted conditions was measured by means of Warburg's manometric technique. No significant differences in oxygen consumption could be demonstrated between these conditions.

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1. Afferent impulses from one more pressure receptor in the depressor nerve of the rabbit have been recorded simultaneously with the arterial blood pressure and ECG.
2. There is a discharge of impulses at all pressure levels in the normal living animal.
3. The degree of activity of the end-organs varies with the blood pressure and is to a considerable extent dependent upon the variations in pressure during the heart cycle.
4. The impulses from a single end-organ are at a maximum frequency during systole.
5. As the pressure increases a larger number of end-organs come into play, the impulse frequency in a single nerve fiber increases, and the discharge continues throughout the greater part of the cycle.
6. Four types of receptors were found. The first responds rather to the absolute value of the blood pressure, the second rather to the rate of pressure change, the third responds when the blood pressure falls and the fourth is superposed on the QRS-complex of the ECG.

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The function of the lateral-line organ of Japanese eel has been examined precisely by means of recording the impulse discharges from a single nerve fiber supplying the organ, which was activated by various kinds of natural and artificial stimulations. The results obtained are summarised, as follows.
1) Examinations by water flow.
With a calm water flow only thin nerve fibers could be excited. Somewhat higher rates of flow first excite the thicker fibers. The aspect of discharges was not changed by the direction of the water flow. The number of discharges from a single nerve fiber increased with increase of the flow rate. The maximum discharge frequency attained was different in fibers with different diameters. The relation between the average number of spikes and the logarithm of the flow rate was nearly linear in every single fiber examined.
2) Examinations by pressure and touch.
Applying pressures of various grades on the skin surface along the lateralline, results were obtained, which were similar to those above mentioned qualitatively and quantitatively. However, some very thick fibers of phasic nature were' very sensitive to the impulse shock and had a relatively low thresholds. They showed sometimes inhibitory phenomena during stimulation, and facilitatoryeffect after the cessation of the stimulation. The lateral-line organ of fish has, too, a dual innervation of slow and phasic fibers, as many other sensory organs have.
3) Examination by mechanical vibrations.In all fibers examined, the discharges were seen to appear in every cycle of mechanical vibrations, provided that the vibration frequency was relatively low. With very low frequencies we had generally a few spikes in each cycle, which changed into one-for-one relation in the middle range of frequency (20-50 cps.). When the stimulus frequency was further increased, there appeared the discharge deficit oftener, the more frequent the stimulus. The largest frequency producing one-for-one appearance of the spikes was different in different fibers, owing to the different diameters. The thicker the fiber the higher it was. The thinnest fiber could follow the vibrations of under 10 cps. only. On the contrary most of the thicker fibers could follow those of 50 cps., and the thickest one even to those near 100 cps.
4) The D. C. stimulation of the receptor easily evokes the iterative firing of the nerve fiber. The average number of spikes had a linear relationship with the logarithm of the current strength. The threshold for repetitive discharges could not be determined precisely, but it was certain that weak currents made the thinner fibers discharge more easily than the thicker fibers. Many fibers were excited by the ingoing current and a few by the outgoing one.
5) The A. C. stimulation of the receptor evoked, also, discharges in every stimulus cycle. For the low stimulus frequency there were a few spikes in the negative phase only. With the increase of the stimulus frequency the number of spikes in one stimulus cycle decreased gradually, to become the one-for-one appearance, to random falling out of the spikes, and finally to a stage where there resulted only one impulse in many stimulus cycles. The maximum frequency for one-for-one appearance of the spikes was related to the fiber diameter, the thicker fiber being able to follow a higher frequency. The upper limit could not be determined owing to the disturbances brought by the stimulus current itself.
The strength of the stimulating current caused changes in the aspect of the discharges. Namely, an increase in strength brought more spikes to appear in the negative phase. With very low frequency it resulted in some spikes appearing in the positive phase, too. If the stimulus frequency is high, and if the current is sufficiently strong, then the one-for-one appearance of the spikes continued to follow much higher frequency, than when it is weak.

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1. Facilitation and inhibition were subjected to experimental examinations, by employing models. for synapse constructed with Lillie's nerve models variously combined or modified.
2. Facilitation easily occurred as a restilt of interaction between two models without any direct connection, but inhibition never occurred in our investigations.
3. Facilitation and inhibition due to temporary increase and decrease of number of “pre-cellular” active elements (dendrites) were clear and definite. on this experience, a new hypothesis of facilitation and inhibition was proposed, which explains satisfactorily the temporal courses of facilitation and inhibition revealed by Lloyd (11).
4. If granted that the β-deflection and γ-deflection (or soma-potential) discovered by Renshaw (14) are due to the activations of dendrites and axon-hillock (or axon itself) respectively, then our hypothesis helps us to understand the changes in size of β-and γ-deflections in inverse directions when examined by lengthening the intervals between the conditioning and test impulses. Facilitation and inhibition of antidromic impulses are also explainable.
5. The positive cord potential in association with inhibition was regarded as due partly to the anelectrotonic regions which will be produced in every resting neurone or fibre neighbouring an excited, and partly to the positive after-potential of β, which is supposed to be representing the dendrite activation.
6. Based on a result obtained during the course of the experiments, axocellular inhibitory coil aterals connecting neighbouring neurones were postulated. This explains the inhibitory action of an antidromic impulse on adjacent axons discovered by Renshaw (17), and also presents itself as a significant mechanism for adjustment of movement.
7. The hypothesis of Eccles and Gesell, particularly the former, were criticized, and a few points of disagreement were presented.

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In the present investigation it was demonstrated that the polarographic method is excellent for the analysis of experiments on adsorption from solutions. By this method the adsorption of lead ions from a lead nitrate solution of low concentration by active charcoal, ox hemoglobin, egg albumin and gelatin was investigated and it was found and shown that the adsorption isotherms in all of these cases are discontinuous. A hypothesis is presented regarding the mechanism by which the discontinuity in adsorption isotherms occurs. It was found that molecular weight of proteins can be determined simply and accurately by applying the discontinuous isotherms. The.molecular weights obtained by this method are for ox hemoglobin 6.8×10⁴, for eg albumin 3.38×10⁴ and for gelatin 4.5×10⁴.

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1. The auto-rhythmic contractions in excised toad's bladder or in muscle strip cut from it are irregular in general, but show regularity to a certain. degree, when the muscle strip is made. small enough.
2. Both end portions of a muscle strip contract independently of each other, whatever changes the one portion might undergo by the local application of some agent, temperature, drugs etc.
3. Direct current flowing along the whole length of the preparation can arrest the auto-rhythmic contractions. They disappear also in states of tonic contraction caused by intense single induction shock.
4. The influence of drugs suggests rather the neurogenic nature of the bladder automatism.
5. It is concluded that the irregular automatic contractions in the bladder are composite movements consisting of numerous localized automatic contractions, which originate from, their respective pacemakers.

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1. Accommodation curves of whole nerves and single nerve fiber muscle preparations of a Japanese toad were measured by exponentially increasing currents. With whole nerves, the bending of accommodation curves was found in about 40% of all determinations, and in two such cases changes of site and manner of muscle contractions were observed.
2. In single nerve fiber muscle preparations, the strict linear relationship, between current strength and time-constant of current rise was obtained.
3. These results give us the conclusion that the bending of the accommodation curve was produced by excitations of other nerve fibers which have a higher threshold and a slower accommodation.
4. Veratrine, guanidine and aconitine, in appropriate concentrations, lower the threshold and decrease the minimal current gradient Of the nerve fiber.

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1) Histological studies showed that the lateral-line organ of fish is innervated by a number of thin and thick nerve fibers. Each thick fiber, ramifying repeatedly, innervates several cells in the central part of the organ. Each thin fiber branches into many more and are connected to many peripheral cells.
2) The electro-physiological, combined with histological, studies of the lateralline sense organ strongly suggests a peripheral neural mechanism of higher sensory organs, that is:
A single end organ is supplied by many thin and thick fibers, among which the thinner fibers are probably related to the threshold, that is, to the perception of stimuli, while the thicker fibers to its discrimination.

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A certain length in the middle portion of a Lillie's nerve model was covered with paraffin, so as an activation wave approaching it has to jump over it for further conduction. The paraffined part was made sufficiently long, so that a single wave could first pass it when the immersion time was made correspondingly long. At a shorter immersion time, a certain number of successive waves were needed for the occurrence of one transmission.
Under such an arrangement, examinations were made on
1) N-I-relation, where N is the number of waves needed, and I the stimulation interval, that is, the immersion time,
2) NI-I-relation,
3) i-I-reration, i being the current flowing over the paraffined part. The results showed that N increased inversely with I, while NI showed a minimum point in relation to I. On the other hand, i increased with I until it attains its highest value at an interval of about 1-2 minute.
The appearance of the minimum point was attributed to the variation of iassociatiated with changing I. It was supposed that a similar state might happen in a nerve, and that, then, the rhythm of excitation for producing the minimum NI will be characteristic to each nerve, and further that if a nerve is excited with this particular rhythm, it will be significant in economizing the time for realizing the transmission.

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1. Toad's bladder responds to various types of electric current with phasic and tonic contractions. The response to indirect stimulation delivered to the vesical nerve consists almost exclusively of phasic contractions. Responses due to direct stimulation consist of both phasic and tonic components contained in different proportions depending on the current form. Response to A. C. stimulation consists, alike indirect stimulation, mainly of phasic components, while those to intense single induction shock and intense D. C. are almost exclusively tonic.When an A. C. is made into an unidirectional pulse current by passing through a vacuum tube, the response becomes strikingly tonic.
2. Phasic contractions can be propagated in nature, and are actually propagated to a certain degree according to the nature of the tissue. Conditions necessary for evoking phasic contractions are considered qualitatively similar to those of nervous impulses or twitches in skeletal muscle.
3. Tonic contraction is nothing more but a temporary change in grade of contracture or tone. It can not be conducted and does not show the all-or-none relation. Its occurrence has some relation to the duration of unidirectional current flow, as well as to current intensity.
4. Weiss' formula applies considerably well with strength-duration curve measured by taking phasic contractions as indicators. Rheobases were 3-5μA, chronaxie 0.35-0.4 sec. at 20°-25°C

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1. Slow rise in temperature within the range of 0°C. and 30°C. brings about shortening of detrusor muscle of toad's bladder, which will be a contracture in nature.
2. In muscles which are found in somewhat contracted states by the effects of high temperature, K ion, Ba ion or aretylcholine, direct current of moderate intensity induces relaxation of muscle as a whole. This relaxation can be explained to be due to marked inhibition of preexistinz contracture in the anodal region, which overcomes the potentiation of contracture in the cathodal region.
3. Muscles in low temperature exhibiting extremely slow contraction as a result of electric stimulation respond to sudden rises of temperature by extension, provided that the temperature change takes place when the muscle is in a contracted state above a certain degree.
4. The maximal heights of contraction evoked by direct stimulation with alternating currents of equal duration are always the same, irrespective of temperature differences lying between 0°C and 30°C., when measured from the lowest base-line which corresponds to the resting length of the muscle at 0°C.

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1) Two nerve fibers of the Japanese toad were dissected out and their accommodation curves were measured by applying exponentially increasing voltage.
2) The small fiber has a larger value of λ than the larger fiber.
3) In most cases two accommodation curves of the large and small fibers cross each other, and when the spike, which was elicited with a lower voltage at any time-constant of voltage rise, is taken as the index of excitation, the socalled “break-down” of the accommodation could be imitated.

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Four young female students subjected to the mental strain of calculating unit figures continuously showed a remarkable decrease in the number of circulating eosinophils (average of 26 per cent in two hours). The result suggests that the pituitary-adrenocortical system was stimulated to such a degree that the “alarm reaction” was initiated, and that the circulating level of cosinophils was lowered due to mental strain.

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1) At the final stadium of bleaching the yellow color exhibited by the retina or the extract of the retina of toad six hours after hepatectomy with ligation of posterior vena cava is deeper than that of the control,
2) If the retinae are turned to the dark before the yellow color has been decolorized by illumination, more visual purple regenerates in those of the toad undergoing hepatectomy with ligation of posterior vena cava than the control.
3) These phenomena occur only in medium which is slightly acid.
4) These phenomena are due to the retarded thermal decomposition of indicator yellow of the toad undergoing hepatectomy with ligation of posterior vena cava.
5) These phenomena occur in the retina of toad undergoing incomplete hepatectomy, ligation of hepatic artery, ligation of portal vein or ligation of posterior vena cava, but hepatectomy with ligation of posterior vena cava is the surest method and requires the shortest time to induce these phenomena.
6) The acid liberation of the retina is almost the same in toad undergoing hepatectomy with ligation of posterior vena cava and in normal toad.

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The diurnal change in circulating eosinophils was studied in four healthy men in the daily routine of laborartory life. The maximal level was obtained at night during sleep, and the minimal in the daytime. Moreover, individual habit seems to play some part in the diurnal rhythm in eosinophils. The second observation of eosinophils in two men with short duration of sleep at night indicated significantly that a continuous sleep might be required for an efficient recovery from stressful performance.

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1) A suitable apparatus for perfusing the frog's heart, by which the metabolic action, mechanical work and electrical response of the heart can simultaneously be observed, was described. The relationship between the oxygen consumption, cardiac output and heart rate was studied to detect the most suitable conditions for making the tests.
2) The effect of drugs can be investigated by adding them into the circulating blood, and blood samples can be taken at will for chemical analysis.
3) Seasonal variations in the activity of the heart were demonstrated, and it was proved that these changes depended partly upon the lactate content in the blood.

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