1. A new method of separating the cone cells and colored oil globules from the cone retina of a tortoise is reported.
2. The extract of isolated cone cells of the tortoise is observed to show a difference in the spectrum with three maxima in 650 mμ(red), 560mμ(yellow green) and480mμ(blue). But these maxima are inconstant.
3. The change of spectral absorption of the alcohol or digitonin extract of colored oil globules due to illumination coincides with that of the extract of cone cells in yellow green, and blue spectral ranges.
4. The presence of vitamin A₂ in the cone retina of a tortoise can not be demonstrated, owing to the interference of the colored oil globules.

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Deflections of ST-T in E.C.G., produced by constant current flowing through the heart, were studied in toads.
1. In the E.C.G. led usually in situ, the deflection varied individually and according to experimental conditions, but some regularity could be found under suitable conditions on the same individual. The deflection of ST-T was reversed with reversed direction of the current and disappeared with cessation of the current. The degree of the deflection was proportional to the current strength.
2. In E.C.G. taken directly from the excised heart, the nearer the recording electrode was placed to the applying, the greater the deflection of ST-T was, and its direction indicated that the potential became higher at the anodal and lower at the cathodal region. Just after the cessation of the current the deflection was reversed.
3. The electrogram led from the sinoauricular preparation with intracavity leading showed a similar deflection during atrial systole and even during passive deflation.

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With pregnant individuals at different stages, cases of abortion and premature delivery, and cases of abdominal inflation, the oblique and straight muscles were investigated electro-myographically with the following results.
1. At the very early stage of pregnancy, the EMG of the oblique muscles showed very weak or no, activity at rest. With the progress of pregnancy, the activity weakened further and disappeared totally after the2nd month. The activity reappeared at about5to20hours before the onset of uterine pains.
2. Active electrical discharges were observed in the cases of abortion and premature delivery. The cases of ascites and ovarian cyst, or pneumoperitoneum showed active discharges in the oblique muscles and sometimes in the straight muscles.
3. The three pregnancy tests were performed on the early stage individuals and the results were compared with the findings of EMG. A fair possibility to use the EMG method for the early detection of pregnancy was demonstrated.

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Crossed reflex of the limb, observed in decerebrate or spinal animals, has not been recognized in healthy man, although it occurs in patients with central nervous disorders. The author, however, showed it can also be elicited in healthy man under suitable conditions.
To the subject, seated with legs hanging free, one of the following three kinds of stimuli was given, and the ensuing reflexive movement of the limbs as well as the EMG of relevant muscles were recorded.
1. Mechanical tapping of the patellar tendon of one side, which produced reflex extension of ipsilateral and contralateral knee joints, reflex flexion of ipsilateral elbow, and reflex extension of contralateral elbow. In the ipsilateral femoral rectal muscle, there appeared two series of synchronous discharges, the primary and the secondary, with latency of20-30msec. and90-150msec. respectively. In the contralateral mate, a synchronous discharge occurred90-150 msec. after the stimulation. The primary discharge is obviously responsible for the ipsilateral knee extension, while the secondary discharge is regarded to cause reflex extension or flexion of other limbs.
2. Electric stimulation with a single shock applied to the skin covering the knee extensor muscle of one side, which produced a similar result.
3. Passive flexion of a knee joint, which gave rise to reflex extension of the contralateral knee joint. This conforms with Philippson reflex in pattern. Also the tonic and the phasic patterns of this reflex could be demonstrated by executing passive flexion slowly or abruptly.
4. Central reflex time in these crossed reflexes was calculated from the above mentioned experiment to be 60-90msec. Further, the mechanism of occurrence of the silent period of discharge was discussed.
Acknowledgment. The author wishes to thank Prof. K. Hukuda for helpful suggestions and criticism during the course of this investigation. A part of expenses of this research was defrayed from the Research Fund granted by the Ministry of Education.

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1. Excitability changes in ventral root fibers during the course of the VRP were examined with excised toad's spinal cord.
2. During the course of the VRP, an increase in the excitability was observed on the ventral root close to the cord. The time course of the excitability change was in accord with that of VRP recorded from the same spot.
3. Spatial spread of the hyperexcitability was examined along the ventral root. The largest increase in the excitability was found in close proximity to the cord, which declined exponentially as the test electrode was moved distally until it faded out somewhere about10mm apart from the cord. At a marginal region, distal from where any excitability change failed to appear, VRP was frequently recorded as a slight positive deflection. Even in this region an in creased excitability was observed. This kind of positivity in VRP was thus accounted for by the volume conductor effect of the ventral root.
4. The results were attributed to the catelectrotonic change in the root fibers which was responsible also for the potential changes in these fibers.

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By thermal analysis of the reaction velocity, the influences of cyanide and azide upon the catalatic reaction by blood catalase (red cell suspension and hemolysate) has been examined. As cyanide and azide, KCN and Na N₃ were used. The inhibition of the reaction has been discussed from the stand-point of adsorption theory. The results obtained are summarized as follows:
(1) The reaction type is not different by the addition of cyanide from that of the standard reaction in the absence of cyanide and is mainly of the first order, except at the initial stage. As the amount of cyanide is increased, the duration of time of the initial stage increases and the velocity constant of the first order reaction decreases.
(2) The reaction type deviates from that of the standard reaction at the initial stage when azide is added, but is mainly of the first order. The velocity constant of the first order reaction decreases as the amount of azide is increased.
(3) CN^-and N^-₃ions have a special affinity and can be selectively adsorbed on the blood catalase surface and retard the reaction velocity by ionic adsorption which is the absorption of potential determining ion.
(4) From the relation between the activity and the concentration of azide, it is considered that there are at leat two kinds of active centres in a blood catalase molecule and N^-₃is combined with one of the two alone.

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The effect of surface-active agents on the catalatic reaction by hemolysate was investigated by the method of thermal analysis of the reaction velocity and the relation between reaction velocity and surface tension has been considered. The results are summarized as follows:
1. The surface-active agents essentially accelerate the catalatic reaction by hemolysate with a certain range of their concentrations, whether or not they are cationic, or anionic, or nonionic.
2. The reaction type is mainly of the first order when the surface-active agent is added, and the maximum of the reaction velocity takes place at concentrations near to the critical micelle concentration giving the minimum on the surface tension-concentration curve.
3. The acceleration by surface active agent is due to the molecular adsorption of a surface-active agent to the blood catalase molecule.
4. The retardation of the reaction velocity comes out only when the concentration of the surface-active agent is very high as compared with the critical micelle concentration, owing to the accumulation of a surface-active agent.
Outline of this report was read before the32th general meeting of Japanese Physiological Society (1955).

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Utilizing a silver microelectrode of5-10μE in diameter insulated by a glass coating, impulse discharges subsequent to adequate stimuli on various parts of the body were recorded from the cervical posterior funiculus of cat and their arrangement was studied.
Conclusions are as follows:
1) Responses were obtained ipsilaterally and the forms of spikes could be classified into two types. One is thought to be related to nerve fibre and the other to nerve cell.
2) Responses to touch on the skin or hairs were most frequently obtained. In them, the amplitude of spikes was generally large and adaptation was very quick. Receptive areas for them were fairly localized, particularly restricted on the distal ends of limbs.
3) Impulse discharges responding-to push or pull of the skin were tonic, adapting slowly. The physiological function of these afferents may be partly proprioceptive.
4) Among proprioceptive afferents, which generally adapted slowly, those for muscles were far less frequently encountered than those for articular capsules or tendons.
5) In Goll's funiculus, responses from tactile afferents were far more frequently obtained than those from proprioceptive afferents. The circumstances were quite opposite in regard to Burdach's funiculus. The majority of responses from the thoracic level seems to be concerned with respiratory movements of the chest.
6) From a localized superficial portion of Goll's funiculus closely adjacent to the septum medianum, slowly adapting impulse discharges were obtained subsequent to filling the urinary bladder. Their spike apperances were far smaller than those for tactile afferents.
7) The medio-lateral arrangement, upon the transverse section of the second cervical cord, of those parts of the body from which the responses were obtained was as follows:(a) urinary bladder, (b) tail or perineum, (c) toes of hind limbs, (d) distal half of hind limbs except toes, (e) proximal half of hind limbs, (f) loins or abdomen, (g) chest, (h) toes of fore limbs, (i) distal half of fore limbs except toes, (j) proximal half of fore limbs.
8) Spontaneous impulse discharges, which were obscure in their receptive fields, were frequently recorded in the lateral half of Burdach's funiculus and in an area between Goll's and Burdach's funiculus. They are assumed to be related to slowly adapting afferents and to be proprioceptive in nature.

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Surface potential of the excised toad's muscle, mostly sartorius, was recorded by a method similar to that used by Burns and Paton (1). Distribution of the surface potential along the length axis of muscle was demonstrated as a curve on a cathode-ray tube.
1. Surface potential of an intact muscle is almost equal, demonstrating a difference of less than 1 mV. When 10^-4-10^-5 ACh chloride is applied, one or two negative peaks appear in the pattern of surface potential. This peak is due to ACh depolarization of the end-plate membrane. If a fine electrode is used, the shape of this peak becomes sharp.
2. Actions of ACh in sodium-free media were studied. It was proven that ACh depolarization of the end-plate occurs in a sodium-free medium where sucrose Ringer and NH₄⁺ Ringer are mixed at an even rate (table 1). After being soaked in this medium, the muscle tested shows ACh depolarization just as in the pre-treatment stage. A vigorous ACh contracture is also observed. The results seem to support strongly the short circuit theory of end-plate depolarization (2, 3, 5, 6, 7, 8).
3. Patterns of ACh depolarization were recorded in several different muscles other than the sartorius. Two types of patterns are found in ACh depolarization. In the first type, which is represented by the sartorius muscle, the peak is sharp and distinct. In the second type, which is represented by the rectus abdominis, the peak is flat. It is considered that muscles which belong to the latter group are composed mostly of tonus fibers.

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Rhythmical spontaneous contraction of the external anal sphincter and bulbo-cavernous muscle in unanaesthetized spinal dogs is inhibited by quickly increasing internal pressure in the urinary bladder. From experiments of dividing and stimulating the pelvic and hypogastric nerves, the nervous pathways for this reflex were found to be as follows.(1) Afferent nervous pathways run through both the pelvic and hypogastric nerves, enter the spinal cord through the posterior root of the lumbar and sacral cord.(2) Efferent nervous pathways from the spinal cord run through the pudendal nerves.

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1. The intraretinal action potentials (EIRG's) were recorded with superfine electrodes (less than 1μ) located at different depths in the retina. Actual depths of the electrode within the retina were carefully controlled by means of a combination of the methods of 1) confirming the electrode tip to be just on the retinal surface at the start of each experiment, 2) correcting errors in the micrometer readings due to the mechanical resistance of the retinal tissue to the penetrating electrode, and 3) measuring the thickness of the retina.
2. Alternate micro-and even illuminations of the retina provided another method of the control. By a weak microillumination of the retinal region where the electrode was situated, action potentials were detectable only when the electrode was within the retina. This was found useful as a measure of depth, particularly when the electrode was inserted from the receptor side of the retina, the thickness of which could not be measured.
3. The EIRG's due to microillumination or the focal potential were almost purely negative everywhere within the retina, being most active in the bipolar layer. Their nature was discussed in connection with the origin of the ERG.
4. Recordings of the EIRG's due to even illumination upon the whole retina confirmed the previous result (21) obtained by means of bigger microelectrodes.
5. After the removal of the focal potential changes by strychnine, the configurations of the EIRG's were much alike and similar to the normal ERG, but their amplitudes depended upon the depths. The changes in the amplitudes of a-, b-, and d-wave in them went nearly in parallel, and were most distinct during the electrode excursion within the bipolar layer, implicating a main origin of all the fast components of the ERG in this layer. Some contribution of other retinal layers to the ERG was thought probable, but the isolation was not successful with the present method.
6. The result was favored by a supplemental experiment with the use of a “pencil electrode”, which was originally designed for simultaneous recording of intra-and extracellular action potentials.

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The effect of different kinds of detergents on the resting potential of muscle was observed in extirpated twin gastrocnemii of bullfrog for further elucidation of the relation electrogenesis in a living organism bears to the adsorption or to the structure of the biological membrane.
The following is a brief description of the results reached.
(1) An ionic surface-active agent at a low concentration brought about a marked reduction in the potential of the uninjured part of muscle and had hardly any such effect on the injured part. A non-ionic agent had hardly any action on either of the parts.
(2) It was found that the correlation between the concentration of a detergent and the change it produces in the resting potential of muscle is explicable by the equation below:
C/E=A'+B'C
where A' and B' are constants. It was presumable that there was a parallelrunning relation between the potential change produced by the detergent and the amount of the detergent adsorbed according to Langmuir's adsorption isotherm.
(3) The velocity with which the detergent acted was determinable by Wo. Ostwald's equation formulated for measurement of toxic actions.
(4) Hardly any correlation was recognizable between the surface activity of a detergent and the change it produced in the resting potential of muscle.
(5) A detergent applied produced muscle contracture and made the surface of the muscle white and turbid.
These results showed that the potential a detergent (6 different kinds used) can affect is on cell membrane; that a detergent is essentially different from any inorganic ions in the mechanism of action; that it is likely to affect the resting potential because its monomolecular adsorption to the surface of membrane may alter the molecular structure of the membrane by its own penetration or by the consequent disorientation of the component molecules of the membrane.

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Cicada's heart action potentials were studied by both surface and intracellularelectrodes. 1) Surface electrograms indicate that the inricate tracingsof the action potentials are due to the presence of alary muscle. After theremoval of alary muscle, the picture became simpler. It was found that thenegative deflection became pronounced at the2nd and the 7th segment. 2) From the results of transverse section, localized cocainization and localizedcooling, it seems reasonable to assume that the cicada's heart has two pacemakers. 3) Intracellular recording from single fibers of cicada's heart showmuscle action potentials of a very simple monophasic form, from which theoscillation of surface potential is concluded to be due to the sum of many othercomponents.

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In decerebrated cats the effects of water-pouring into the pharyngeal cavityupon the discharges of a single inspiratory neurone of the normal respiratorycenters were studied. The results can be summarized as follows:
Pouring the water into the pharynx always inhibits the discharges of theinspiratory neurones. When the swallowing act is elicited by water-pouring, the inhibition described above is interrupted by a burst of impulses lasting0.067-0.083seconds.

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1. Based on the equation derived recently by myself on the relation betweenan active length x, and the resting length, y, which can be activated by x, theroles of membrane resistance and safety factor being played for conduction, were examined.2. The ratio of resting to active membrane resistance, rm/r'm, or the ratioof length constant of resting to active membranes, k/k', was found to play animportant role, together with the safety factor, f, for local excitation, for realizingthe all-or-nothing conduction. Generally, f decreases with increase ofthe ratio. The value of f for infinitely large ratio is unity. It seems verylikely that the necessary condition is satisfied with ample reserve in the squidgiant axon.3. Conduction velocity increases with rm until it attains maximum at a certainrm. The safety factor, f, decreases with rm and attains a certain definitevalue at the critical rm. This value decreases in inverse proportion to (1-e-x/k'), and attains e² at x/k'=∞. The theoretical value for the squid giant axon isjust about e², while a rough estimate of the actual value is7-8 or eventuallylarger than 10. The significances were discussed.4. The smaller the resistance r'm the larger is the conduction velocity andthe smaller the minimal active length, L, required for starting an impulse. 5. It was concluded that large rm and small r'm co-operate intimately withf for enhancing the “safety of conduction” in generalized sense.

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1. The effects of strychnine upon the nerve fibres of toads were investigated.
2. Strychnine had little effect on the myelinated portion, while it had markedeffects on the node of Ranvier.
3. The rheobasic voltage of the node was decreased by the application ofstrychnine solutions of lower concentration (from about10^-17M to10^-5M), butwas increased by higher strychnine concentrations (more than10^-4M).
4. The rheobase of the node in Ringer solution rose by strychnization of theneighbouring node.
5. Thesholds for repetitive response to constant current was decreased bystrychnization of the fibre. The decreased threshold for repetitive response pro-duced by strychnization of the fibre was hardly possible to be restored to theinitial value by washing the fibre with fresh Ringer solution.
6. The relative refractory phase of nerve fibres became shorter than in thenormal, and the supernormality of the fibre was increased and prolonged by weakstrychnization, but the recovery process was depressed by strong strychnization.
7. The strychnine concentration, which was necessary to decrease therheobase of the fibre, became high by raising the room temperature over20°C.
8. Repetitive responses due to single shock stimulation were observed instrychnine-treated nerve fibres (from about10^-7M to10^-4M) at temperatureshigher than about20°C.

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Experiments were made on somatic areas I and II of the unanesthetizedcat to produce the flexion of contralateral forepaw by electrical stimulation. Insomatic II, there was little evidence to support Garol and Woolsey's results (6, 10), since the flexion limited to contralateral forepaw could be produced fromany point in this area. Between somatic I and II, no remarkable difference wasrecognized in threshold value of motor response ; influence of duration of singlepulse upon threshold of motor response ; latency before the appearance of motorresponse ; influence of varying interval between two pulses upon character ofmotor responses. Moreover, the phenomenon of summation was recognized oneach or both somatic I and II.

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In this study the interconnections between somatic areas I and II (limb) of the cerebral cortex of the cat have been studied by means of electrical stimulation and electrical recording. It was confirmed that bilateral somatic areas I and II receive impulses from the superficial radial nerve and the saphenous nerve. It was also found that somatic areas I and II have connections with each other not only in the homolateral but in the contralateral cerebral cortex.

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The fine structure of the frequency spectrum of the EEG of both resting condition and photic stimuli application led from the occiputs of healthy adults was analysed by120ordinates multi-harmonic analysis (time for analysis-approximately2sec. Resolving power for frequency-approximately0.5c/s.), and the following result was obtained:
(1) What may be regarded as line spectrum was not found in the EEG frequency spectrum. In most cases, on each band of delta, theta and alpha waves, a certain number of peaks were seen. No outstanding peak was detectable among the beta waves. Not a few cases were suggestive of the fact that the band of alpha waves should be extended to 9-14c/s. or 7-15c/s. instead of limiting it to8-12or13c/s.
(2) It has hitherto been considered that photic stimuli cause alpha waves to diminish and beta waves to appear, but though the alpha wave peaks of low frequency do diminish with moderate stimulating effect, those of high frequency grow larger or new peaks appear. Contrary to what has hitherto been believed, beta waves diminish under photic stimuli.
When the stimulating effect is great, all the alpha wave peaks diminish; a part of the beta wave peaks temporarily rises while the other part diminishes.
(3) Although delta waves show no definite type of change under the photic stimuli, theta waves tend to diminish.
(4) When the stimulation lasts longer, a certain number of alpha waves begin occasionally to appear in group on the EEG tracing. The frequency spectrum in this part shows not only the recovery of the peaks corresponding to the principal peaks immediately preceding the stimuli application, but also the remaining peaks of higher frequency. Those of low frequency also tend to appear.
(5) From the above result it was found that some waves in alpha wave band show the reaction contrary to each other to photic stimuli, suggesting that some waves involve different physiological significance.

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(1) Effects of glutamate and its metabolite on the respiration of isolated outersegments of rods were studied by means of the Warburg apparatus at26°C. The outersegments were separated from dark adapted toad's retina.
(2) l-sodium glutamate had a powerful effect on the respiration in both dark and light conditions.
(3) In the dark condition, l-sodium aspartate showed a remarkable depressive effect on respiration. l-asparagine and r-aminobutyric acid had a similar, but weaker, effect.
(4) NH₄ ion markedly inhibited the effect of illumination on the respiration of outersegments of rods.α-alanine and γ-aminobutyric acid showed a similar effect. But their effect was weaker than NH₄ ion.
(5) A hypothesis on the matabolic cycle in the outersegments of rods was advanced.

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The authors investigated effects of mercaptide-forming agents on the mechanical and electrical activity of the toad's isolated heart.
1. Cadmium chloride reduced and at last arrested completely the heartcontraction. Changes in the electrocardiogram were the prolongation of the PQ-interval, the shortening of the ST-interval, and the decrease of the amplitude of the R-wave and the T-wave. Sometimes a reversal of the T-wave was observed. At last, the P-wave disappeared. A prominent change of the myocard monophasic electrogram was a shortening of the duration.
2. Effects of mercuric derivatives, such as p-chloromercurobenzoic acid or phenylmercuric acetate were principally the same as the effect of cadmium chloride.
3. The ECG and monophasic myocard action potential survived the standstill of the heart with mercaptide-forming agents. This was seen with Cadmium chloride of 10^-4 or 10^-3 M.
4. The Changes in the mechanical and electrical activity of the heart with mercaptide-forming agents were corrected almost completely with cysteine hydrochloride or thioglycollic acid.

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In measurements of the photosensitivity of the eye the use of strong test stimuli is carefully avoided, because the state of adaptation of the eye is disturbed by such test stimuli. Little precaution has, however, been taken to avoid strong electric stimuli in measurements of the electrical sensitivity of the eye, because it has been believed that electric stimuli which cause only weak sensations of light have no disturbing effect upon the state of the eye.
1. It was found that electric stimuli of a few volts or a few hundred, μ2A have a strong depressing effect on the electrical sensitivity of the eye, and that this effect lasts as long as one hour.
2. After application of several electric stimuli of the mentioned order at an interval of7seconds, the determination of thresholds became extremely difficult, and in consequence the accuracy of measurements is strongly affected. For example, the standard deviation (S.D.) of10threshold values determined by the routine method was0.27% of the average. Prior to the determination of each threshold value, 10shocks of2volts were given at an interval of7seconds. The S.D. became7.9%, that is, about30times as high as the value obtained without the conditioning shocks.
3. Keeping this after-effect in mind, a method of equal logarithmic steps proposed by Riggs was criticized.

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The author applied thermal stimulation to electrochemical models immersing the core in the warmed solution and obtained relation between the temperature (T) and stimulating time (t) under various experimental conditions.
1. The T-t curve is approximately the same to strength-duration curve in the nerve or muscle, though there are some differences due to the kind of the solution or other conditions.2. In warming solution with recovering power, (t) for the same (T) becomesl onger according to the intensity of recovering power. But when the solution contains stimulating agent, (t) for the same (T) becomes shorter according to the magnitude of the agent contained.
3. When the thermal and electrical stimulation are applied in combination, they act either cooperatively or antagonisticaly according to the direction of the current.
4. Hydrogen ions contained in the warming solution produce remarkable differences in T-t-relation, its higher concentration brought shortening of (t) according to its rate. The concentration and kind of other positive ion have scarcely any influence on the T-t curve.
Discussing these results, the author obtained the following conclusions.
Excitation with thermal stimulation will be caused thus, that the movement of hydrogen ion is activated by the increase of temperature and increase of ionswhich penetrate the excitable membrane and results in loss of excitable membrane samely as in the case of electrical stimulation on the electrochemical model, but the ultimate establishment of this view must await the result of future studies.

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1. In an anatomical study of the toad's sinus venosus, it was found that the muscle fibers are not homogenously distributed. The main muscle strands started from a point situated about3mm. above the left hepatic vein. It formed the fan-like tissue (Uchiyama).
2. By using a small heating thermode, various parts of the sinus venosus were heated locally. The highly thermo-sensitive region was found to coincide with the sites of Remark's ganglia.
3. After the removal of ganglia or the application of nicotine, localized heating of the sinus venosus failed to cause tachycardia.
4. The possible relationships between the thermo-sensitive region and the localization of the cardiac pacemaker are discussed.

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Seven dogs, anesthetized with evipan-sodium, were experimented on. The adrenal venous blood specimens were collected through the lumbar route and the adrenaline content of the specimens was estimated colorimetrically by means of the arseno-molybdic acid method of Bloor and Bullen.
On receiving acetylcholine in a dose of2mg. per kg. the adrenaline secretion of the adrenal gland was remarkably augmented and its mean value during90 seconds after the start of injection was estimated as0.41-0.97μg. per kg. perminute.
After a while, hexamethonium in a dose of0.25-1.0mg. per kg. was applied and then acetylcholine in the same dose as before was injected again. In all cases, except in one instance when hexamethonium was given in a dose of0.25 mg. per kg., the value after the2nd acetylcholine injection was noticeably small, 0.02-0.14μg. per kg. per minute being estimated there.
From these experimental results, it is deducible that the adrenaline-secretory effect of acetylcholine is inhibited by hexamethonium.

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1. In male albino rats, adapted to live at29.5°C. for a period of more than 8weeks, and then exposed to cold environmental temperature between10°and 15°C. for 10 days, a rise in oxygen consumption occurred. The histological picture of the thyroid indicated hyperactivity of the gland. However, change in the level of PBI was small.
2. In the heat adapted rats, which were successively given vasopressin or oxytocin, there was no significant change in oxygen consumption. However, the level of PBI became lower in the case of vasopressin but not in the case of oxytocin. Histological picture indicated a slightly depressed activity of the thyroid after vasopressin and also after oxytocin.
3. Rats were adapted to live at29.5°C. for the same time and then exposed to cold temperature between10°C and15°C. for10days and they were successively administered with the posterior pituitary hormone during a period of cold exposure. In the case of vasopressin the rate of rise in oxygen consumption and the level of PBI were remarkably lower than that of control ones which were exposed to cold but not given any vasopressin. Histological examination also showed an evidence of inhibitory effect on increasing of thyroid activity due to cold exposure. In the case of oxytocin these effects were hardly found.

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1) A rapid increase in bladder pressure regularly caused an increase in contraction of the stomach and inhibition of the small intestine. Tne motor response was usually produced in the dog which has a strong peristaltic contraction of the stomach. The inhibitory response of the small intestine was reversed to a motor response by applying nicotine to the coeliac plexus.
2) The motor afferent nervous pathway is the pelvic nerves, and this can also be demonstrated by the central stimulation of the pelvic nerves. Tne inhibitory afferent nervous pathway is the hypogastric nerves which can also be demonstrated by the central stimulation of the hypogastric nerves.
3) The efferent nervous pathways of the motor and inhibitory response of this reflex are contained in both the splanchnic and vagus nerves.

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The attempt was made to cover the thermoelastic behavior and the selective permeability to ions of the cornea by taking into account the presence of negatively charged ionized groups fixed on the protein chains.
The tension-temperature relations of the cornea were determined, and the entropic and energetic contributions to the net tension were calculated on the basis of the thermodynamic considerations.
Over the range of moderate extensions,
(1) positive tension is due entirely to the entropic contribution,
(2) the internal energy makes a negative contribution to the tension.
These results can best be explained by the superposition of two systems which oppose each other, i.e. an entropic system and the other in which electro-static repulsion between charged groups of like sign causes the tension.
e long chain molcules bearing ionized groups of like sign can thus be envisaged as a sort of “elastic double system” the repulsion of these groups to stretch the chains, whereas the thermal motion of the segments tends compress them.
Further evidence for the presence of ionized groups on the protein chains was provided by the experiments on the permeability to ions. The concentration chains with the chlorides of Na, K and Ca were measured; from the values of the P. D.'s the mobility ratios of the cations and anions within the stroma
The anion mobility is relatively more supressed within the stroma as com-pared with the cation, i.e. the stroma, is permeable selectively for cations. This could satisfactorily be explained by the negatively charged ionized groups of the protein molecules.
Further, the fiber arrangement was studied in detail, and the radial fibers are, in the polarization optic sense, considered as dominant.
The diagram is given showing a possible submicroscopic structure which can cover the known mechanical and optical characteristics and also the selec-tive permeability to ions.

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By means of a microelectrode technique the experiments were performed to contribute to the solution of the question on the localization, as well as on the automaticity, of the respiratory centers in the catfish and the crucian carp. The results are summarized as follow:
1) When at the region of the boundary of the acoustic tubercle and the facial lobe in the catfish, and at the region situated rostro-laterad to the lobus impar in the crucian carp, the microelectrode was inserted dorsoventrally half of the length of the dorso-ventral diameter of that region, the volleys consisting of spike discharges were detected recurrently with the rhythm of the movements of the gill covers.
2) The histologic studies revealed that the tip of the electrode reached the region situated dorsad to the substantia gelatinosa Rolandi which was located dorsad to the motor trigeminal nucleus.
3) In the brain stem which was isolated rostrad from the lobus opticus and caudad from the spinal cord, and in which all the brain nerves were cut, the volleys whose aspect was similar to that of the volleys observed before the isolation of the brain stem were detected from the region described in 2).
4) From the results described above, it was concluded that the respiratory centers of the catfish, as well as those of the crucian carp, are most probably endowed with the ability to discharge with inherent rhythmicity.

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The influence of stimulation of the lumbar ventral root and the dorsal root on the distal colon has been investigated. The chief results thus obtained may be summarised as follows:
1) In anesthetized and unanesthetized dogs, peripheral stimulation of the ventral root (L₂-L₇) constantly caused an ihibitory effect of the distal colon, and the dorsal root stimulation (L₂-L₇) caused always a motor effect. However, the reverse effect did not occurred under any condition.
2) The effect of ventral stimulation was abolished after blocking the inferior mesenteric ganglion by application of nicotine or a C₆-solution. However, the effect of dorsal root stimulation was not influenced by the block of the ganglion. This shows that the inhibitory fibers have nerve-cells in the inferior mesenteric ganglion, however, the motor nerve do not have any nerve-cell connections in it.
3) The motor effect is augmented by eserine solution and abolished by atropine.

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1. By means of pencil electrode, simultaneous intra-and extracellular recordings were made of the action potentials in the lateral eye of the horseshoe crab (Tachy_pleus tridentatus). A method of compensation was combined to minimize the capacitive coupling between the inner and outer pipette of the pencil electrode and also to reduce the effective input capacitance of each pipette.
2. The obtained result confirmed the conclusion in a separate paper (12) that the ommatidial action potential has its origin a little distance from the site of impulse generation. Discussion was made more about the mechanism.
3. The membrane resistance of photosensitive cells within ommatidia was found to re-increase during illumination in the wake of sudden decrease at the onset of illumination, providing an explanation of the fact that the off-deflection far smaller than the on-deflection in the extracellularly recorded ommatidial action potential.
4. The light adaptation affected much the height of initial peak of the ommatidial action potential, but its effect on the following steady level of depolarization was small.
5. Occasionally, the membrane was inflicted a local inactivation by the tip of microelectrode.

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