PHYSIOLOGY. 



579 



The residue is sometimes more, sometimes less 

 digested than the nitrogen-free extract. Crude 

 fiber may be changed during digestion so as to 

 appear as nitrogen-free extract in the excrement. 

 The determination of sugar, starch, and pentosan 

 is more important than that of crude fiber. 



The observations of V. Harley indicate that 

 the digestive power of pepsin is not affected by 

 dry heat that is, by three hours' exposure, at 

 100 C., over sulphuric acid. The action of heat 

 on pepsin in solution is very different, however, 

 a temperature of 82 C. in the experiment de- 

 scribed causing its destruction. At temperatures 

 below 75 C. the disaggregation of fibrin was 

 complete in tw r enty-four hours, but at 81.5 C. 

 the fragments of fibrine were only softened super- 

 ficially; and at 82 C. the pepsin had no effect 

 whatever, even after twenty-four hours. 



In 1898 (see Annual Cyclopaedia for 1898) Dr. 

 Carl Schlatter, of Zurich, reported a case of com- 

 plete extirpation of the stomach, and proved from 

 the physiological condition of the patient sev- 

 eral months afterward that only the slightest 

 effects on the function of digestion had followed 

 the operation. He has more recently described a 

 case of resection of about six feet of the small 

 intestine without the patient suffering serious 

 injury. The patient was an Italian who had 

 been stabbed in a brawl, and was found, upon 

 examination about nine hours afterward, to have 

 a protrusion of the bowel, the exposed part of 

 which was already dying. The affected part was 

 cut out, and the ends of the other parts were 

 sutured together. The patient rallied fast, and 

 steadily improved in health and weight, so that 

 he left the hospital in good condition. The 

 chemical examination of his diet and excretions 

 showed that the percentage of absorption of 

 nitrogen was fully up to the normal, but that 

 there was a greater loss of the fat in the food 

 than should have occurred in health. His subse- 

 quent history, however, was not quite so favor- 

 able. Eight months after the operation his 

 weight had decreased, and he was not able to 

 tolerate the solid food to which he had previously 

 been accustomed. Yet, while he felt unequal to 

 much work, he was regarded as on the whole in 

 a very fair condition. 



In his Hunterian lectures on the Surgery of 

 the Stomach, Prof. Mayo Robson has more fully 

 shown that large portions of the stomach may 

 be excised, or even the whole removed, with no 

 very great mortality, and in successful cases with 

 little effect upon the patient's digestion. In the 

 present opinion of the medical profession the 

 stomach hardly occupies so important a position 

 in digestion as it formerly held. It is now re- 

 garded as rather a preparer for the exercise of the 

 digestive powers of the pancreas than as itself an 

 active digestive agent. One of its functions is to 

 render innocuous many of the micro-organisms 

 which enter with the food. 



The relation of the cell to the enzymes or solu- 

 ble ferments which originate from cells was 

 touched upon by J. Burdon Sanderson in the 

 address he delivered before the International 

 Medical Congress at Paris. Formerly, the speaker 

 pointed out, each kind of cell was regarded as 

 having a single special function proper to itself, 

 but the progress of investigation has shown that 

 each species of cell possesses a great variety of 

 functions, and that it may act upon the medium 

 which it inhabits and be acted upon by it in a 

 variety of ways. Thus, for example, the color- 

 loss corpuscles of the blood (or, as they are now 

 called, leucocytes) are considered not merely as 

 agents in the process of suppuration or as typical 



examples of contractile protoplasm, but rather 

 as living structures possessing chemical functions 

 indispensable to the life of the organism. Simi- 

 larly, the blood disk, which formerly was thought 

 of merely as a carrier of haemoglobin, is now re- 

 garded as a living cell possessed of chemical sus- 

 ceptibilities which render it the most delicate re- 

 agent that can be employed for the detection of 

 abnormal conditions in the blood. The tendency 

 of recent research is to show that the reactions 

 referred to as chemical functions of the cell 

 (action of the cell on its environment actions 

 of the environment on the cell) are the work of 

 ferments, which are products of the evolution of 

 the living cell, and therefore to which the term 

 enzymes may be applied. Recent researches have 

 plainly indicated that in the case of the disease- 

 producing micro-organisms the specific functions 

 which for years were regarded as proper to, and 

 inseparable from, the cell, belong essentially to 

 the enzymes which they contain. It has been 

 further shown that similar statements can be 

 made as regards ferment processes which differ 

 widely from each other, and no less widely from 

 those induced by bacteria. So that in the domain 

 of microbiology the enzyme may in a certain 

 sense be said to have " dethroned the cell." 



In the first part of his Microscopic Researches 

 on Glycogen, published in 1896, Dr. Charles 

 Creighton gave the details of his observations on 

 the character and functions of glycogen in the 

 embryos of mammals, and showed how he had 

 been led to regard it as the precursor, the tem- 

 porary substitute, or the accessory of red blood. 

 In the second part of the memoir, published in 

 1899, he has described the distribution of glycogen 

 in the invertebrates, the mode in which and the 

 period w r hen it is deposited in various examples, 

 and has developed the view which he has been 

 led to adopt. The solid carbohydrate starch or 

 its modification is regarded as the blood of vegeta- 

 bles, and in the author's opinion glycogen or ani- 

 mal starch is co-ordinate in value with the blood 

 or lymph of animals. He finds it not unreasonable 

 to look upon starch as a fixed instead of a fluid 

 nutriment. A substance resembling starch in com- 

 position but differing from it in giving a red reac- 

 tion with iodine, has long been known, and evi- 

 dence is adduced from the observations of chemists 

 and biologists showing how much attention has 

 been given to the subject, and how wide is the 

 distribution of animal starch. It has been found 

 in protozoa, less distinctly in ccelenterata and 

 worms, very clearly in the chief families of mol- 

 lusks, and in arthropods. In the higher mollusks, 

 which have been the special object of the author's 

 investigations, it is accumulated around the ves- 

 sels and is contained in the large plasma cells, 

 around those of the nerve centers and of the di- 

 gestive and nerve tracts, or exactly in those parts 

 which are nearest to the sources of supply and 

 those in which the most active processes are taking 

 place. In the arthropods it is also found in the 

 organs of reproduction, as well as elsewhere, at 

 certain stages of development. The plasma cells 

 in the mollusks mentioned here, with their con- 

 tained zo-amyline, occupy the position of the vas- 

 cular sheaths of the vertebrates; and as the tis- 

 sues in the vertebrates derive their pabulum from 

 the lymph which circulates in the perivascular 

 sheath, so the tissues of the mollusca draw their 

 nourishment from the carbohydrate stored up in 

 the plasma cells. In Ihe vertebrates the original 

 vascular system of the molluscan series no longer 

 contains a lymphlike fluid, but is filled with red 

 blood. 



M. Bouchard reports to the French Academy of 



