542 



PHYSIOLOGY. 



panied by secretion causes a diminution in its 

 volume so marked that in most cases it over- 

 powers the effects of any simultaneous vasodila- 

 tation. ISince there is no diminution in the lymph 

 ilow from the gland, but rather a slight increase 

 during the period of stimulation, we must con- 

 clude that the effect of the secretory nerves is 

 simply and solely upon the secretory cells, the 

 increased exudation from the blood-vessels which 

 must in the last instance supply the fluid for the 

 secretion being a secondary phenomenon deter- 

 mined entirely by the metabolic changes of the 

 cells and lagging behind these to a considerable 

 extent. There is no evidence to show that a sym- 

 pathetic secretion is brought about through the 

 medium of a muscular mechanism. 



In a study of the gaseous metabolism of the 

 submaxillary gland, with especial reference to the 

 effect of chorda activity on the respiration of the 

 gland, Mr. Joseph Bancroft, of Cambridge, found 

 that, during the excretion of saliva induced by the 

 stimulation of the chorda tympani, the oxygen 

 taken from the submaxillary gland was increased 

 to an amount three or four times that taken up 

 by the resting gland; that the carbonic acid given 

 out by the gland was increased under the same 

 circumstances to an equal or even greater extent; 

 and that after an injection of atropin sufficient 

 to cause paralysis of the secretion, the intake of 

 oxygen by the gland was not increased by stimu- 

 lation of the chorda tympani, while, on the other 

 hand, the output of carbonic acid was increased, 

 at least for a time. 



Experiments made by Drs. Gull and Fowler in 

 the study of the question whether the spleen is 

 connected with the production of blood-corpuscles 

 gave results as to the blood entering and leaving 

 the spleen that there was no difference in the 

 blood of the splenic vein and the splenic artery, 

 and further, that removal of the spleen (of the 

 dog, rabbit, and cat) produced no perceptible 

 change in the number of the corpuscles of the 

 blood; and that the recovery of the number of 

 corpuscles after hemorrhage and hemolytics pro- 

 ceeded as fast in animals without spleen as in 

 those with spleen. 



In a preliminary communication on the metab- 

 olism of creatinin, J. J. R. Macleod sets forth 

 several facts of peculiar interest which presented 

 themselves in his investigation, especially with 

 regard to variations in the quantity of that sub- 

 stance excreted in urine in various diseases. The 

 experiments indicate that creatinin excreted by 

 urine may be divided into an endogenous and an 

 exogenous quotient, the former arising from the 

 metabolism in the animal's own tissues, the lat- 

 ter from the creatin and creatinin introduced in 

 the food. Since the total amount of creatinin 

 excreted, therefore, must vary with the diet in the 

 omnivorous animal, it is necessary, in studying the 

 variations in the excretion of this body in the 

 intestine, to place the patient on a creatinin-free 

 diet. This was done in several diseases, more espe- 

 cially in muscular atrophy and splenic enlarge- 

 ment. In the former disease no diminution was 

 found. In splenic enlargement, however, a dimi- 

 nution of the excretion of about 50 per cent, was 

 obtained. Reasons are given for supposing that 

 the diminution is probably not dependent on the 

 number of leucocytes, but on the size of the spleen. 

 In other words, it would appear that the spleen 

 exercises some influence on the metabolism of cre- 

 atinin. 



The evidence afforded by the experiments of 

 Prof. Gley, of Paris, on the function and inter- 

 dependence of the thyroid and parathyroid glands 

 was both chemical and biological. The author 



regarded the parathyroids as complemental in 

 functions and structure to the main thyroid. 



Secretions. In a paper communicated to the 

 Royal Society by Benjamin Moore and W. 11. 

 Parker evidence was brought forward that the 

 bile exercises an important action as a solvent; 

 and this the authors claimed to be the chief, if 

 not the only, function of that secretion. It was 

 pointed out that the bile in this respect has a two- 

 fold action: first, in aiding the secretion of cho- 

 lesterin and lecithin; and, second, in aiding the 

 absorption of fatty acids and sodium soaps from 

 the intestine. All these substances possess a low 

 solubility in water, and have their solubility in- 

 creased in bile chiefly by the virtue of the prop- 

 erties of the bile salts. The fact that cholesterin 

 is but slightly soluble in bile explains the fact 

 that gall-stones are composed almost exclusive- 

 ly of that substance, while lecithin is very solu- 

 ble in bile, and hence is never deposited. This 

 view as to the action of the bile is regarded as 

 also furnishing an easy explanation for what is 

 called circulation of the bile, and as accounting 

 for the faulty absorption of fat in the absence of 

 either bile or pancreatic juice, and the almost com- 

 plete failure of fat absorption when both of these 

 excretions are excluded from the pancreatic canal. 



Studies are reported by Prof. Moussu, of Alfort, 

 of the lymph flow in the limbs of the larger ani- 

 mals (horse, ox, etc.) during repose and inaction 

 and then under conditions of local vasoconstric- 

 tion and vasodilatation and under those of gen- 

 eral augmentation of blood-pressure and of copi- 

 ous venous depletion. The author had further 

 observed the lymph flow under the influence of 

 muscular work afid under conditions of great 

 activity. The general conclusions reached by him 

 are that the lymph is not a simple product of a 

 translation from the blood-plasma through the 

 capillary wall under the mechanical pressure of 

 the blood circulation; that filtration is always 

 quite a minor factor in the production of lymph; 

 that the lymph is mostly a product of the tis- 

 sues comparable to a secretion from them; that 

 the quantity of its production is in direct rela- 

 tion to the functional activity of the tissues; and 

 that the peripheral (limb) lymphatic apparatus is 

 in large measure an apparatus for secretion. 



Studies of the effects of venous obstruction on 

 the secretion of urine by D. H. De Souza go to 

 show that ligature of the renal vein is not fol- 

 lowed within the duration of an ordinary experi- 

 ment by coagulation of the blood within the vein 

 or its branches. Obstruction of the renal vein, 

 whether partial or complete, always caused dimi- 

 nution or cessation of urinary secretion, which, 

 however, was not immediate. The flow, of urine 

 from the kidney was directly proportional, other 

 things being equal, to the velocity of the blood 

 flow through the kidney. The nature, of the 

 glomerular function must be regarded as still 

 undecided. Secretory activity on the part of the 

 cells of the glomerular epithelium is still un- 

 proved, and the majority of the facts may be ex-, 

 plained without ascribing to this epithelium other 

 than a purely passive function as a filtering mem- 

 brane, impermeable in most cases to proteids. 

 Such an explanation, however, throws all the 

 work of regulation of urinary composition, either 

 in a positive or negative direction, on the cells of 

 the urinary tubules. 



Watery extracts of the pituitary body have 

 been found by R. Magnus and E. A. Schafer to 

 produce rise of blood-pressure by contracting the 

 systematic arterioles, much in the same way as 

 extracts of suprarenal medulla produces its well- 

 known pressure reaction. 



