rie 



PHYSIOLOGY. 



of the intestines is subject to inhibitory and aug- 

 mentor impulses dependent, first, on the condi- 

 tion of the neighboring parts of the organ: and, 

 second, on impulses ascending to the central 

 nervous system from the intestine, abdominal 

 wall, and other parts of the body, and affecting 

 the nerves reflexly. The motor mechanism of the 

 intestinal wall is, moreover, extremely sensitive 

 to changes in the blood flow through the vessels 

 of the intestine, or to the presence of drugs or 

 other chemical substances in the blood or within 

 the intestine itself. The subject has been investi- 

 gated by W. B. Bayliss and E. H. Starling, who 

 find two kinds of movements distinguishable in 

 the small intestine the rhythmic pendulum 

 movements, due to rhythmic contractions a fleet- 

 ing longitudinal and circular coats simultane- 

 ously, myogenic in origin, and peristaltic con- . 

 tractions, true co-ordinated reflexes. The activ- 

 ity of the intestinal muscles will at any time de- 

 pend on the relative influence of the two sets of 

 impulses inhibitory from above, and augmentor 

 or excitatory from below to which every point 

 of the intestine is subject. Besides these local 

 influences, every point of the intestine is under 

 the control of the central nervous system through 

 the intermediation of the splanchnic and the 

 vagus nerves. The splanchnic nerves exercise a 

 tonic inhibitory influence on the intestinal move- 

 ments, excitation of them causing inhibition of 

 the intestine affecting the longitudinal and cir- 

 cular coats, which is independent of the vaso- 

 constrictor action of the splanchnics. No satis- 

 factory evidence was obtained that these nerves 

 possess a motor function. The vagus nerves con- 

 tain two sets of fibers inhibitory and aug- 

 mentor. The inhibitory fibers have a short latent 

 period, the augmentor fibers a long latent period. 

 The action of the vagus on the intestines is there- 

 fore twofold an initial inhibition followed by 

 augmentation which outlasts the extinction of 

 the nerve. The vagi have no tonic action on the 

 small intestine. The relations of the vaso-con- 

 strictor and vasomotor and of the splanchnic 

 nerves to the small intestine and the action of 

 certain drugs upon them have also been investi- 

 gated by J. L. Bunch. 



From a study of the structure and functions 

 of the glands of the stomach, pursued chiefly 

 from a histological point of view, Dr. R. R. 

 Bensley holds that the present state of our knowl- 

 edge does not permit any comparison between 

 the pyloric glands and the other glands of the 

 stomach, and that they can not be compared with 

 any of the gastric glands of the lower inverte- 

 brates. He believes that the pyloric gland cells 

 are in most animals closely allied to certain cells 

 in the neck of the fundus glands which have up 

 to the present time been regarded as ordinary 

 chief inconspicuous cells, and that those of the 

 cat, dog, and rabbit are identical with them. The 

 author's researches have enabled him to satisfy 

 himself that in the fundus glands of many mam- 

 mals there are cells which are morphologically 

 and physiologically equivalent to the mucous 

 neck cells of the batrachian gland, and that the 

 same relationship exists between these and the 

 pyloric gland cells as obtains in Anura. These 

 cells in the neck of the gland have been in great 

 measure overlooked on account of their small 

 size, and are generally regarded as pepsin -secret- 

 ing chief cells. In the cat and dog, Dr. Bensley 

 holds that the fundus glands contain two kinds 

 of chief cells those of the body and those of the 

 neck of the gland. The former secrete ferment 

 and present numerous large zymogen granules 

 accumulated near the lumen, while the outer 



protoplasmic zone of each cell dyes deeply with 

 nuclear dye like hnpmatoxylin and presents a 

 coarse fibrillar structure. The staining proper- 

 ties of this part of the cell are due to the pres- 

 ence of a kind of chromatin which may stand in 

 a genetic relation to zymogen, and which has 

 been named pro/ymogen. He regards the cells of 

 the neck of the gland and the cells of the pyloric 

 gland, for reasons which he assigns, as of the 

 same nature. The chief cells of the neck of the 

 fundus glands and the pyloric gland cells of tin- 

 cat and dog are the physiological and morpho- 

 logical homologues of the mucous neck cells :md 

 pyloric gland cells of the frog, with which they 

 correspond in situation, structure, functional 

 cells, and staining. The cells of the lowest por- 

 tion of the gland duct or pit are of a type inter- 

 mediate between the surface epithelium and the 

 mucin-secreting neck cells or pyloric gland cell-, 

 and form the fundamental type' to which the ori- 

 gin of both must be traced. 



Dr. Southgate and B. K. Rachford published in 

 1805 the results of some experiments on the in- 

 fluence of bile and combined hydrochloric acid 

 upon the proteolytic action of pancreatic jui.-e. 

 Their conclusions "having been questioned, Mr. 

 Rachford made further experiments, by the evi- 

 dence of which he is led to believe that the Con- 

 ditions prevailing throughout the entire sum II 

 intestine in carnivorous animals are favorable to 

 the proteolytic action of pancreatic juice. In 

 those animals, when the proteid food parth sat- 

 urated with hydrochloric acid is discharged from 

 the pvlorus, it at once comes in contact with 

 the mixture of bile and pancreatic juice, and im- 

 mediately the trypsin finds itself under condi- 

 tions most favorable for its proteolytic action. 

 These conditions prevail for a short time only, 

 when the pancreatic juice, more or less weakened 

 by dilution as it passes down the intestinal canal, 

 is* called Ujxm to act in the presence of soil i um 

 carlmnate in the lower and alkaline portion of 

 the ilium; and here again we find the conditions 

 very favorable for the proteolytic enzyme of tin- 

 pancreas. If the above conditions as assumed l>e 

 correct, then throughout the entire small intes- 

 tine trypsin finds itself in conditions more favor- 

 able to proteolytic action than if it were acting 

 throughout the* canal on neutral fibrin in neutral 

 solution. 



The question of what detrimental effects, if 

 any, does the excessive formation and absorption 

 of indol a substance produced in some amount 

 in the intestines of most adult human beiir 

 the result of bacterial action on proteids entail 

 upon the human organism is the subject of a 

 paper by Dr. C. A. Herter. The indol produced 

 in the intestine is oxidized within the organism 

 into indoxyl, which, in combination with -ul- 

 phuric acid as indoxyl potassium sulphate, forms 

 the basis of the well-known indoxyl or indiean 

 secretion of the urine. This reaction is in various 

 derangements of digestion often more pronounced 

 than in health, which suggests the inference fhat 

 an unusual quantity of urine has been formed in 

 the intestine and absorbed from it. The author 

 considers himself justified by his study and ex- 

 periments in believing that prolonged and 

 sive indol absorption is capable of causing head- 

 ache, especially frontal headache, abnormal ce- 

 phalic sensations, and indisposition for mental 

 and physical exertion. The latter condition, if 

 prolonged, may perhaps form the basis of a neu- 

 rasthenic state. The subject is one for further 

 study. 



Secretion. The known facts with regard to 

 the secretion of urine are explained by 



