bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE DEVELOPMENT OF THE ELASMOBRANCH PITUITARY
Authors: Herring P. T. 
Published: December 2014

The early stages of development of the elasmobranch pituitary resemble closely the early stages of development of the mammalian pituitary, with this difference—that there is no invagination of the wall of the cerebral vesicle in the elasmobranch to form an infundibular lobe.The pituitary of the elasmobranch is developed entirely from Rathke's pouch, i.e. from buccal epithelium.The general relation of the pituitary to the ventricles of the brain is, in elasmobranchs, similar to that obtaining in the higher orders of vertebrates, but this is accounted for by the development of a paired saccus vasculosus, each of which pours its secretion into a common infundibular canal.The wall of this so‐called infundibular canal is lined with epithelium similar in character to that lining the saccus vasculosus. Its nervous structure is lost, being replaced by connective tissue and numerous thin‐walled blood‐vessels. There is no invasion of the wall of the canal by epithelial cells, and no hyaline bodies are formed.The pituitary body of the elasmobranch is a gland, the secretion of which is poured directly into the blood‐vessels. There is no evidence of any direct secretion by the pituitary into the brain ventricles.I have to thank Mr Richard Muir for the accompanying illustrations. The expenses incurred have been assisted by a grant from the Carnegie Fund for research work.
THE RELATION OF PROTEINS TO CRYSTALLOIDS. III. HÆMOLYSIS BY ALKALI. IV. HÆMOLYSIS BY HYPOTONIC SODIUM CHLORIDE SOLUTIONS. V. HÆMOLYSIS BY RISE OF TEMPERATURE
Authors: Roaf H. E. 
Published: December 2014

1. Addition of alkali to sodium chloride causes an increase in the osmotic pressure of a hæmoglobin solution in equilibrium with it.2. This increase of pressure runs parallel to the hæmolytic action of the alkalies.3. Therefore hæmolysis by alkalies may be due to an increase in the osmotic pressure of the hæmoglobin contained in the corpuscles.4. The experiments failed to show that hæmolysis by acid is accompanied by an increase in the osmotic pressure of the hæmoglobin, but such a possibility is discussed.5. Hæmolysis by dilution is probably the result of a temporary difference of osmotic pressure.(a) If the corpuscle wall is impermeable to sodium and chlorine, a difference in pressure of over 1000 mm. of mercury exists before hæmolysis occurs.(b) The osmotic pressure of hæmoglobin does not show an increase corresponding to hæmolysis by dilution.6. Hæmolysis by rise of temperature may be due to the increase in the osmotic pressure of hæmoglobin.7. The relation of cells to inorganic substances can be explained without the assumption that the cell membrane will not allow these substances to pass through.
REFLEX INHIBITION OF SKELETAL MUSCLE
Authors: Forbes Alexander 
Published: December 2014

1. There appears to be no foundation for the view accepted by some that inhibition results from stimulation of assimilation in excitable tissues.2. The dynamic features of the crossed extension reflex and its inhibition in the preparation used by Sherrington cannot be explained in full under all conditions in terms of assimilation and dissimilation in the moto‐neurones as discussed by Hering.3. There are several reasons for believing that the increased response to a given excitatory stimulus following prolonged inhibition and the “rebound contraction” following brief inhibition are essentially different phenomena.4. Inhibition when opposing excitation in this preparation does not delay fatigue in the excitatory arc.5. The effect of prolonged inhibition upon subsequent excitation depends on the strength of the inhibitory stimulus. With moderate stimuli it favours subsequent activity, with strong stimuli it depresses it.Exceptional cases are found, probably always after impairment of ventilation, in which every strength of prolonged inhibition causes subsequent depression of excitatory response.6. The “critical value” of inhibition at which it neither improves nor impairs subsequent excitatory activity appears to be lowered if the excitatory arc is stimulated during the prolonged inhibition.7. Prolonged inhibition fatigues some part of the inhibitory reflex arc, and impairs its subsequent response.8. There is evidence, to be published in detail later, showing that fatigue as demonstrated in both excitatory and inhibitory arcs does not involve the centre as a whole, but only the particular path employed.9. Possible explanations of “subsequent augmentation” and “subsequent depression” are discussed.
RESEARCHES ON THE PERFUSED HEART: THE EFFECTS OF INORGANIC SALTS
Authors: Burridge W. 
Published: December 2014

It is shown that many substances may produce heart block if they be perfused through the heart at a too high pressure.The salts of potassium may be divided into two groups with reference to their action on the heart of the frog. This division is determined by the presence or absence of a “contraction effect,” when the salts are employed in high concentration. The absence of this “contraction effect” with the one group of salts is shown to be due to their action on some of the calcium salts of cardiac muscle. All the salts temporarily abolish the rhythmical activity of the heart.The division of the salts into these two groups is in accord with their action on the sartorius muscle.Potassium salts give rise to two types of contraction in the cardiac muscle of the frog, viz., the “tonic contraction” and the “contraction effect.” The former could be produced by all the salts of potassium examined, and seemed to be in some way associated with the rhythmical contraction process; the latter was the determining factor for dividing the salts into two groups, and could be produced in the non‐beating heart.There is a seasonal, and also individual, difference in the action of a 0·225 per cent. solution of potassium chloride on the frog's heart. In any heart, and at any season, the seasonal differences found in the fresh heart may be reversed or paralleled by appropriate treatment with calcium or potassium salts. The conclusion is drawn that there are seasonal variations in the balance between the calcium and potassium salts in the heart muscle of the frog. It is possible that temperature may be a factor in bringing about such changes.There are at least three groups of calcium salts in the cardiac muscle of the frog.The salts of one of these groups seem only to be displaced by such potassium salts as the oxalate and citrate. The results obtained after such displacement suggest that these salts are normally concerned in bringing about some limitation of the direct action of potassium salts on heart muscle.The other calcium salts are readily displaced by all potassium salts. Such displacement is followed by derangement of spontaneous contractions and of rhythm, such as to suggest the loss of some form of governing or controlling influence. Since restoration to the normal depends on calcium salts, these would appear to keep the cardiac functions in check in addition to being essential to their initiation. Irregularities of rhythm and contraction may appear independently of each other, and for this reason the calcium salts governing these processes are divided into two separate groups. The calcium salts controlling rhythm also appear to mediate the action of the vagus nerve on the heart.In conclusion, I wish to express my sincere thanks to Professor Gotch for his valuable criticism and advice.
AGE AS A FACTOR IN THE EFFECTS WHICH FOLLOW THYROIDECTOMY AND THYROPARATHYROIDECTOMY IN THE SHEEP
Authors: Simpson Sutherland 
Published: December 2014

1. Removal of the thyroid with the contained internal parathyroids in thirteen adult sheep and sixteen lambs from seven to eight months old, led to practically no ill effects.2. As the result of a similar operation, three lambs about two months old became typical cretins.3. The complete operation (thyro‐parathyroidectomy) in four adult sheep was followed by no symptoms during the time (three to four months) they were under observation.4. The same operation (thyro‐parathyroidectomy) in four young lambs (five to seven weeks) resulted early in acute and fatal tetany.5. Removal of the two external parathyroids from the three cretins when about one year old was followed by only slight symptoms.With regard to the effects both of thyroidectomy and of parathyroidectomy in the sheep, age is a very important factor.
ON THE RESISTANCE TO ASPHYXIA OF THE DUCK IN DIVING
Authors: Huxley Frances M. 
Published: December 2014

In the duck, the relation between the rate of the heart and that of respiration is very close. With inspiration, as in mammals, there is quickening of the heart‐rate; with expiration, slowing, which becomes marked if this phase be prolonged. Thus slowing or stoppage of breathing, however produced, causes a corresponding slowing of the heart—the length of the pause, not the agency which produces it, being the important factor.Thus submersion of the duck's head gives rise to slowing of the heart, because it produces apnœa; occlusion of the trachea, on the other hand, causes but little change in respiration, and under its influence slowing of the heart is less marked.Slowing of the heart and the fact of apnœa aid the duck in resisting asphyxia from submersion, because oxygen is spared by the decreased metabolism of the heart and respiratory muscles, and by the absence of mechanical circulation of the air in the respiratory tract.One reason why, in the duck, asphyxia in air is more rapid than in water must be that in this case there is little sparing of oxygen in this way.
THE CHEMISTRY OF THE MAMMARY GLAND
Authors: Campbell J. Argyll 
Published: December 2014

I. Analyses of mammary gland tissue from lactating bitches and cats show that considerable differences exist between different parts of the same gland, between glands of the same animal, and between glands of different animals of the same species.II Lactose is only found when the gland contains milk. It is not found in the gland of a pregnant animal. Most of it can be removed by draining the gland, so that the amount present is a measure of the milk content of the gland.III. Since lactose is not a constituent of the parenchyma cells, it must be formed from some other substance in the process of secretion into the alveoli.IV. The fat obtained from the gland cannot be taken as an indication of the amount of milk constituents it contains, because fat is found not only in the parenchyma cells in the milk within the alveoli, but also as adipose tissue between the alveoli.The subject of this research was suggested by Dr Cramer, to whom I have been indebted for advice.The expenses have been defrayed out of the Earl of Moray Fund, University of Edinburgh.
THE ACTION OF PROTOVERATRINE AND ACONITINE ON THE NEURO‐MUSCULAR APPARATUS OF THE FROG
Authors: MacNaughton Marjory 
Published: December 2014

1. The action of protoveratrine upon nerve fibres, when tested by the method of rapid serial stimulation, the muscle response being used as an index of the processes occurring in the nerve, closely resembles that of yohimbine. A protoveratrinised nerve shows “fatigue” upon activity and recovery after rest. A rest of several minutes is sometimes necessary before the conductivity of the nerve is restored, There is no “Wedensky effect.”2. There are, however, certain differences between protoveratrine and yohimbine. Protoveratrine produces a more lasting “fatigue” in nerve fibres than does yohimbine. Again, the snap reflex in the frog produced by yohimbine is not produced by protoveratrine.3. The action of aconitine upon nerve fibres is similar to that of protoveratrine.4. Protoveratrine has a special action upon the myo‐neural junction. After this has been exposed to the action of protoveratrine, stimulation through the nerve causes a rapid and permanent “fatigue.”5. Aconitine is without this action.
RESEARCHES ON THE PERFUSED HEART—SOME ACTIONS OF ACIDS AND ALKALIS
Authors: Burridge W. 
Published: December 2014

Alkalis produce two types of ventricular contraction. The one produced by small concentrations of alkali (Gaskell) depends on the calcium salts in the perfusing medium; the other is not so dependent. It is an alkali rigor.Acids produce two main types of ventricular contraction. Certain organic acids produce a slow developing rigor contraction which destroys the contractile material.Certain inorganic acids produce a quickly developing contraction capable of repetition.Lactic acid produces a contraction of intermediate type.The perfusion of acids through the heart changes the normal reaction of the ventricular wall to sufficiently concentrated solutions of calcium or potassium salts. The change suggested is that of altering the permeability of some membrane or membranes to these salts.The physiological neutralisation of an acid is not adequately performed by a bicarbonate but it is by a phosphate.Under the conditions of these experiments the hydrogen ion adversely influences those functions of the heart subserved by the sarcoplasm and its junction with other contractile elements.The actions of the hydrogen ion are determined by the displacement of other inorganic elements in the tissues, calcium salts being important elements so displaced.
THE BLOOD‐VOLUME OF COLD‐BLOODED ANIMALS AS DETERMINED BY EXPERIMENTS UPON FROGS AND LIZARDS
Authors: Fry H. K. , Adelaide M. B. 
Published: December 2014

1. The blood‐volume of cold‐blooded animals, such as frogs and lizards, is satisfactorily expressed in the formula B= Wn/k, where n has a value of about 1·2 and k is a constant to be ascertained for each species.2. The blood‐volume is accordingly neither proportional to the body surface as in the warm‐blooded animals, nor to the body weight.3. It appears, however, as suggested by Dreyer and Ainley Walker (5), to be proportional to the weight of the osteo‐muscular system of these animals.4. A sexual difference is found between male and female frogs similar in character to the sexual difference shown to exist in warm‐blooded animals (4).5. In Meeh's formula for body surface (S = kW⅔) the best n for my frogs and lizards is 0·68, giving an average k of 11·2 for frogs and 11·6 for lizards
FURTHER EXPERIMENTS ON THE RELATION BETWEEN THE ACTION OF CALCIUM SALTS AND ALKALIES ON THE PERFUSED HEART
Authors: Burridge W. 
Published: December 2014

1. A previous finding of the author that the increased tonus which follows the addition of traces of alkali to a solution perfusing the heart is dependent on the calcium salts in the perfusing solution is confirmed.2. It is suggested that this action of the alkali is mediated by a change in the state of aggregation of some of the heart colloids.3. It is shown that the action of the alkali in inducing changes whereby the effective action of a given concentration of calcium in producing tonus is increased, is antagonised by calcium salts.4. It is suggested that calcium salts induce a state of aggregation in certain heart colloids which is unfavourable to their own activity in producing tonus.5. It is shown that alkalies first prolong and then shorten the refractory period of the heart, and that a marked summation of contractions is made possible.
THE DEATH TEMPERATURE OF NERVE
Authors: Halliburton W. D. 
Published: December 2014

1. The irritability of frog'
s nerves was tested by the application of weak induction shocks, and mechanical excitation to muscle‐nerve preparations.2. When the temperature of the Ringer'
s solution, in which parts of these nerves are immersed, is raised, the heated portion of the nerve loses both its excitability and conductivity at the same temperature and at the same moment.3. This temperature is identical with that at which the first protein in the series contained within nerve‐protoplasm enters into the condition of a heat‐coagulum.4. If the heating takes place fairly rapidly (that is, if the nerve reaches and remains at the desired temperature for a few minutes), the death temperature is 40°–41° C.5. But more prolonged exposure to temperatures a few degrees below this effects the same result. The lowest temperature used (36·50°C.) accomplishes this end in a little over an hour.6. This is exactly parallel to what happens when one heats the protein extracted from nervous tissue by saline solution. Opalescence, the initial visible sign of heat‐coagulation, sets in at 36°C., and if the heating is prolonged at this temperature culminates in the production of flocculi.7. It is also paralleled in experiments on the shortening of nerve under the influence of heat; shortening begins at the temperature of opalescence, and although it is not energetic until 40°C. is reached, full shortening can be obtained at the lower temperature provided sufficient time is allowed.8. The abolition of nervous irritability produced by such temperatures is like the heat‐coagulation of a protein in being an irreversible phenomenon.9. Alcock's conclusion that the cause of ilerve‐death at an elevated temperature is due to the coagulation of the first protein is thus fully confirmed.10. This is strengthened by the consideration that in warm‐blooded animals the death temperature of nerve is higher, and is there again identical with the coagulation temperature of the first of the series of proteins contained in this variety of nerve.11. Alcock's method was different from the one mainly used in the present research. He employed the galvanometric response as the “sign of life” in the nerves he used, and heated his nerves for periods of 5 minutes.12. I have, however, in a few experiments used this method also, and find that a temperature as low as 36·5°C. will abolish the electrical sign of life, provided it has been kept up for a little more than an hour.13. v. Miram's results in which he puts the death temperature of frogs' nerves at 47°C., I am wholly unable to explain.I am indebted to the Government Grant Committee of the Royal Society for a grant which has enabled me to pay the expenses of this investigation. A few years ago I placed the research in the hands of my former demonstrator, Mr V. W. Draper, B.Sc., but, after a few preliminary experiments which I have incorporated in the present paper, he was obliged to abandon the work owing to ill‐health.
THE PROPRIOCEPTIVE REFLEX OF A FLEXOR MUSCLE
Authors: Asayama Chuai 
Published: December 2014

1. Quick stretching of tibialis anticus by a sharp pull on its tendon as the muscle lies slack in the decerebrate or spinal preparation (cat) elicits a reflex contraction of the muscle. The reflex is also obtainable in the intact animal under narcosis. It is more marked in the decerebrate than in the spinal preparation.2. The reaction is a proprioceptive reflex, the only afferent nerve required being that belonging to the muscle itself. The tendon of the muscle and the muscular part immediately adjacent to the tendon are not essential for the reflex. It is not therefore a tendon phenomenon, strictly speaking. It may be termed a stretch‐reflex.3. The minimal amount of stretching required to evoke the reaction is very small, a stretch amounting to 1 mm.—that is, less than 1/100th of the total length of the muscle—being sometimes sufficient. A stretch amounting to about 1/13th of the total length of the muscle evoked the reflex in fullest amplitude.4. Rate of stretching is an important factor in the stimulation, a slow stretching, however ample, being apparently unable to evoke the reflex.5. The contraction has often the myographic appearance of a simple twitch, lasting about 1 second; but under certain circumstances it is considerably more prolonged. When well marked, it develops force enough to raise a weight of more than 30 grms.Sometimes the response is multiple, and 2–4 separate twitch‐like contractions succeed each other in quick succession.6. The latent period of the reflex is shorter than that for reflexes evoked from the muscle by other afferent channels.7. When the reflex response of the muscle has been tired out for the ordinary “flexion‐reflex,” this proprioceptive stretch‐reflex persists unaffected by that fatigue.8. Strychnine increases the reflex.
THE PARATHYROIDS:—TETANIA PARATHYREOPRIVA: ITS NATURE, CAUSE, AND RELATIONS TO IDIOPATHIC TETANY. PART I.: INTRODUCTION, GENERAL METHODS, AND SYMPTOMS
Authors: Paton D. NoËl , Findlay Leonard 
Published: December 2014

1. Idiopathic tetany and the various theories as regards its etiology are considered.2. The previous work upon experimental tetany is dealt with in the three periods— (a) before the recognition of the possible significance of the parathyroid; (b) while the distinction between the thyroids and parathyroids was still doubtful; (c) after the direct implication of the parathyroids in the production of the symptoms had been established.The evidence that the condition is a true tetania parathyreopriva is considered to be conclusive.3. The method of removing the parathyroids is considered, and the impossibility of getting rid of the internal parathyroids with certainty by any operation but complete thyroparathyroidectomy is indicated. The existence of supplementary parathyroid tissue in about 50 per cent. of cats and in probably about 5 per cent. of dogs is shown to explain the absence of symptoms in some cases of thyroparathyroidectomy.4. The symptoms of tetania parathyreopriva are considered under the following heads:— I. Their protean character. V. Tremors and fibrillar tremblings. II. Depression. VI. Jerkings. III. Emaciation. VII. Convulsions. IV. Spasticity. VIII. Disturbances of balance.5. Some of the factors modifying the character and onset of the symptoms are briefly considered:— (a) The nature of the food. (c) Rickets. (b) Age. (d) Pregnancy and lactation.
THE PARATHYROIDS:—TETANIA PARATHYREOPRIVA: ITS NATURE, CAUSE, AND RELATIONS TO IDIOPATHIC TETANY. PART V.: GUANIDIN AND METHYL‐GUANIDIN IN THE BLOOD AND URINE IN TETANIA PARATHYREOPRIVA AND IN THE URINE IN IDIOPATHIC TETANY
Authors: Burns David , Sharpe J. S. 
Published: December 2014

The results may be summarised in the following table.Guanidin (and the methyl‐guanidins expressed as guanidin) in mg. per 1000 c.c.— A. Blood. Normal (average of 5) Dogs. Parathyroidectomy (average of 8). 1·0 8·7 B. Urine. Dogs. 0·25 (average of 6) 1·1 (average of 6) Children. Idiopathic tetany. (Average of 5 individuals—8 analyses.) (Average of 3 cases—13 analyses.) 0·12 Active tetany . 0·58 Latent tetany . 0·38 Recovery from tetany 0·12.
STUDIES ON THE ENDOCRINE GLANDS:—II.: THE RELATIONS OF THE PITUITARY BODY WITH THE THYROID AND PARATHYROID AND CERTAIN OTHER ENDOCRINE ORGANS IN THE RAT
Authors: Kojima Masaharu 
Published: December 2014

The effects of thyroidectomy—which was only partial, since it was desired to leave the parathyroids in situ—have been to cause changes in the pituitary consisting in the accumulation of colloid between the cells of the pars anterior, such as has been described by previous investigators, and an especial development of oxyphil cells, as well as the appearance of many swollen—possibly degenerating—cells, some of which are seen to surround clear vesicles. In the case described there was a cyst‐like expansion of the intraglandular cleft in the pars anterior, but whether the result of the thyroidectomy or not, cannot be stated. The pars intermedia was thickened, and contained many vesicles, surrounded by cells, and occupied by masses of hyaline substance. These vesicles extend here and there into the pars nervosa.The chief effect of partial parathyroidectomy was to produce an œdematous condition of all parts of the pituitary. Oxyphil cells appeared more abundantly than usual in the pars anterior, but there were no such striking changes in the gland as are caused by thyroidectomy.
STUDIES ON THE ENDOCRINE GLANDS:—IV.: THE EFFECTS IN THE DOG UPON THE REMAINDER OF THE THYROID AND PARATHYROID OF PARTIAL REMOVAL OF THOSE ORGANS
Authors: Kojima Masaharu 
Published: December 2014

The remaining portion of thyroid after partial thyroidectomy undergoes proliferation of its epithelial cells and the vesicles show marked polymorphism. There is little or no change in the parathyroid.Partial parathyroidectomy causes no apparent changes in the remaining parathyroid tissue nor in the thyroid.