The present experiments were performed with dog's submaxillary gland, (a) for the identification of efferent nervous pathways which mediate the impulse from brain to the submaxillary gland in reflecting the blood tonicity upon salivary salt concentration, and (b) for the elucidation of the mechanism involved therein. The results are as follows:
(1) It was confirmed that the reflection of changes in tonicity of blood upon salivary salt concentrations are effected not only by the direct effect of blood circulating in the gland, but also by the nervous control from the osmoreceptor in the brain. The present experiments revealed that this impulse from the brain is transmitted through three nerves, i. e., chorda tympani, vagal, and hypoglossal nerve.
(2) The function of duct cells being impaired by HgCl₂ injection, the intraglandular activities involved in the mechanism of salt secretion was analysed. The saliva collected from the gland impaired by HgCl₂, presented higher ionic concentration than that from the control gland and the concentration was maintained constant irrespective of variation of rate of salivary flow. It is inferred that the saliva thus collected from the gland treated with HgCl₂ is the precursor saliva secreted from the acinus and the experimental verification by the previous authors that the dependence of the ionic concentration on the rate of salivary flow is effected by the activity of the duct was confirmed. It was verified by the stop-flow analysis that the duct epithelium displays the reabsorption of Na⁺and Cl^-and the secretion of K⁺in precursor saliva.
(3) It was clarified by experiments with the HgCl₂ gland that the nervous impulse mentioned in (1) affects the reabsorption of Na⁺and Cl^-from the precursor saliva running through the duct.
(4) The factors involved in the mechanism reflecting the change in blood salt concentration upon salivary composition were discussed and their quantitative analysis was attempted.

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1. Potential changes in response to antidromic and mechanical stimuli were recorded across an oil-saline interface placed close to or at the non-myelinated terminal of the Pacinian corpuscle, of which the lamellae had been removed up to the central core.
2. An antidromic stimulus produced a diphasic potential indicating that an antidromic impulse can invade the terminal, while a mechanical stimulus generated a diphasic response of an all-or-nothing nature superimposed on a graded response, or on the receptor potential. This all-or-nothing response to mechanical stimuli can be abolished and the antidromic impulse becomes monophasic when procaine, choline or cooling is applied to the terminal.
3. When a mechanical stimulus was delivered within a few msec after an antidromic impulse, the all-or-nothing response to mechanical stimuli was abolished, and only the receptor potential was observed during the refractory period of the terminal. The amplitude of the receptor potential became smaller as the interval between the mechanical and antidromic stimuli was shortened. The depression of the receptor potential could not be observed, when the terminal was made inexitable by procaine, choline and cooling so that antidromic impulses could not invade the terminal.
4: The relative amplitude of the maximum receptor potential, the all-ornothing impulse at the terminal and the mechanically and antidromatically elicited impulses at the first node of Ranvier was measured; their average ratio being 0.49: 0.36: 0.85: 1.
5. The receptor potential has a rise time of about 1 msec and the time constant of decay of its exponential falling phase is 0.9 msec, which is smaller than that obtained in intact Pacinian corpuscles.

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1. Single glass micropipettes were filled with solutions containing various anions and inserted into the soma of the goldfish Mauthner cell (M-cell) and used both for electrophoretic injection of anions and for intracellular recording. In several instances, however, injection of anions and potential recording were made through different barrel of double barreled microelectrodes or through two independent intracellular microelectrodes.
2. The anion injection influenced the spike size as well as the IPSP which were set up by antidromic stimulation of the M-cell.
3. On the basis of the effect upon the IPSP, it was found that the activated inhibitory postsynaptic membrane were permeable to six anion species, Br^-, Cl^-, NO₃^-, SCN^-, ClO₃^- and HCOO^-, and non-permeable to nine anion species, HS^-, BrO₃^-, HSO₃^-, HCO₃^-, CH₃COO^-, SO₄^--, H₂PO₄^-, HPO₄^--and citrate ions. The time constant of the IPSP recovery after injection were assessed for six penetrating anions.
4. A reduction in the spike size was almost always observed after anion injection into the M-cell. The reduction was especially marked after the injection of non-penetrating anions.
5. Antidromic impulse invaded the soma and gave rise to a large spike on top of the usual spike for a short while after the injection of HS^- ions. Invasion of impulse activity into the soma membrane has never been reported so far in the M-cell.
6. Results of anion injection in the M-cell were compared with the results obtained in the cat motoneurons.

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1. Centrifugal action potentials were observed in the cardiac branches of the right vagus of the dog when various sensory nerves were electrically stimulated.
2. Single-pulse stimulation of the sinus nerve reflexively induced impulses in the cardiac branches after a latent period of approximately 60msec.
3. Stimulation of the nerves containing no specific cardioregulatory afferent fiber, such as saphenous and brachial nerves, did not induce impulses in the cardiac branches but nonspecifically inhibited spontaneous impulses in them.

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1. Large amounts of the fresh microsomes prolonged the duration of the clear bphase, and inhibited the syneresis and ATPase of myosin B even in the absence of oxalate. These effects were increased by the addition of oxalate to the reaction mixture.
In the absence of oxalate, the relaxing activity of the microsomes on the clear phase, syneresis and ATPase of myosin B fell off on the storage at 0°C.
2. With the aged microsomes, in the presence of oxalate, the same effects as the fresh microsomes on the clear phase, syneresis and ATPase of myosin B were observed.
3. In the absence of oxalate, the calcium binding activity of the microsomes decreased to about one-fifth to one-tenth of that in the presence of oxalate, and typical “extra” splitting of ATP was not observed even with the fresh microsomes. On the other hand, over 50 times larger amounts of the microsomes than that required in the presence of oxalate was required for 50% inhibition of the myofibrillar ATPase activity.
4. The release of calcium from the aged microsomes was not observed.
5. The protein-free effective eluate was separated in the absence of oxalate and its relaxing activity was not affected by the addition of oxalate.

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1. The effects of some anions (Br, NO₃, I, SCN, substituted for Cl) and cations (TEA, NH₄, substituted for Na) on the membrane resistance and twitch tension of frog skeletal muscle fibres were investigated.
2. In nitrate-Ringer, both of membrane resistance and twitch tension increased in proportion to the concentration of nitrate.
3. The degrees of twitch potentiation by these anions were Cl<Br<NO₃<I<SCN. The increasing factor of membrane resistance was also in the same order, the relative values were Cl:Br:NO₃:I:SCN=1:1.2:1.5:1.7:2.0. But the relation between twitch tension and membrane resistance was not linear. These anions have a facilitatory action on excitation-contraction coupling, besides an increasing effect on membrane resistance.
4. The membrane resistance showed little or no change by TEA substitution, but twitch tension was potentiated far more than expected from prolonged. action potential. Therefore, TEA has the prolonging action on membrane depolarization and the facilitatory action on excitation-contraction coupling.
5. When NH₄ was substituted for 20% of Na, membrane resistance as well as twitch tension showed a transient increase within several minutes, and in 10minutes both of them fell down to steady value. But in 50% NH4-Ringer, the excitation-contraction coupling was blocked in 10minutes, and tension was depressed to the value lower than 30%, despite of the prolonged action potential.
6. The two effects of these anions and cations were discussed; the one is the effect on membrane, increasing the membrane resistance, prolonging the depolarization, thus the twitch tension is indirectly potentiated, and the other is the direct effect on the excitation-contraction coupling.

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The effect of unilateral striatal spreading depression (SD) evoked from hyperstriatum on spontaneous unit activity in different structures not directly invaded by SD was studied in 98 curarized unanesthetized pigeons.
Three kinds of responses, i. e. increased firing, decreased firing and no change were observed throughout structures studied. In brain stem reticular formation the activity of nearly 80% of units (n=35) was changed during striatal SD. The occurrence of decreased and increased reactions was the same. No lateralization of the SD effects was observed. In cerebellum (n=23) and homolateral bulbar sensory nuclei (n=19) reactions were similar as in reticular formation, while in contralateral bulbar nuclei (n=17) significantly more no change responses occurred. Most common diencephalic reaction (68% of units) to homolateral SD was decreased firing (n=28). The occurrence of no change response (8%) in homolateral diencephalon was lower than in reticular units. Contralateral SD (n=16) evoked less decrease (37.5%) and more no change responses (37.5%) in diencephalic units. In contralateral striatum (n=48) most units (58%) remained unchanged and increase and decrease reactions were equally frequent. Data from 4 units of ipsilateral paleostriatum are in agreement with our former findings that SD elicited from hyperstriatum does not enter paleostriatum.
The remote effects of striatal SD in pigeons are compared with those of cortical SD in rats. Differences in the functional organization of mammalian and avian brain are discussed.

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1. In Cl-free sulphate-, ferrocyanide-and glutamate-Ringer's solutions, the frog skeletal muscle fiber showed two different distributions of the resting potentials, one of which had the peak at about -80mV and the other, about-30mV. The difference of the resting Potentials in two groups was clear in K-free solution.
2. The fiber with the low resting potential had a much higher membrane resistance than that of the fiber with the high resting potential. The low resting potential seemed to correspond to the plateau of the prolonged action potential at which both Na and K conductances were inactivated. In such condition, the fiber showed the slow break response after cessation of the strong inward current pulse. The response may be caused by the increase of the K-conductance due to the hyperpolarization. Form of the response was varied depending on the membrane potential level.
3. In K-rich Cl-free solution, the slow break response was also observed after termination of the inward current pulse. This response may be explained by the decrease of the K-conductance due to the hyperpolarization.

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