Hi Investigations on the Life- History 



auce and stains deeply and nearly uniformly with eosin, while in the 

 nucleus the chromatin becomes massed together into a single small 

 shrivelled deeply-staining ball, or breaks up into several smaller balls 

 of that character. It never remains unaltered. The cells presenting 

 these characters may either remain attached to the basement membrane 

 of the glands or may lie in detached masses in the lumen of the glands 

 (Fig. 2). Very often, too, leucocytes wander out from the connective 

 tissue beneath into the glands and lie among the degenerated epithelial 

 cells ; these are generally of the eosinophile variety, but the granules 

 seem soon to lose their distinctive reaction, and the leucocytes can then 

 with difficulty be distinguished from the degenerated epithelial cells. 



Sometimes this mixed mass of cells lies on the surface of the mucous 

 membrane and presents an appearance very much like that to be 

 described in the intestine and pyloric appendages (p. 18). This material 

 probably represents the slimy substance mentioned by Miescher. 



The connective tissue septa lying between the glands fall together, and 

 iu extreme cases the appearance presented is more like that of granu- 

 lation tissue from an ulcerated surface than a mucous membrane. 



Now, it is of course well known that in the stomachs of the higher 

 animals post-mortem changes, and notably post-mortem digestion, take 

 place often with great rapidity, and it was obviously of great importance 

 to make sure that the appearances just described were not due to some 

 such process, especially as the stomachs of the salmon from the higher 

 river reaches could not arrive in Edinburgh in less than several hours. 

 In order to resolve this difficulty, Dr Noel Paton, during the course of ;i 

 fishing excursion, preserved a number of trout stomachs and other parts 

 of the alimentary tract, exactly as had been done with the salmon, some 

 absolutely fresh, others at intervals after death of ten minutes, one hour, 

 two hours, three hours, and six hours. These were all cut and examined, 

 and though I shall have to say more about the pyloric appendages and 

 intestines of these fish, it is not necessary to describe the stomachs in 

 detail, as it was found that even six hours after death there was practically 

 no post-mortem change. It would not have been possible to have dis- 

 tinguished these stomachs from those preserved at once. Even the. 

 superficial epithelium was completely preserved, and the cells of the 

 deeper parts of the glands gave excellent demonstrations of zymogen 

 granules when treated with iron-hsematoxylin, while their nuclei and 

 protoplasm remained unaltered. The connective tissue never showed 

 the hyaline change. All these trout stomachs contained food, generally 

 the remains of small crustaceans or insects, which they were actively 

 digesting, and were therefore precisely in the condition where one 

 would have expected post-mortem digestion to be specially rapid. The 

 salmon stomachs I have described as showing this " catarrhal " change 

 did not contain food and were therefore not active, and it seems there- 

 fore reasonable to conclude that the catarrhal change was not due to 

 this cause. The stomach of the trout may quite fairly be compared 

 with that of the salmon, as it is merely a miniature copy of it. The 

 main points of difference between the two are that in the trout the 

 glands are shorter, the stratum compactum is very much thinner, the 

 connective tissue less in amount, and the muscular coats, of course, not 

 so strongly developed. The minute structure of the different elements 

 of the organ is precisely similar in the two fish. 



Moreover, in some stomachs from the salmon, notably in that from 

 No. 72, which was caught at sea, we had an opportunity of seeing the 

 change which really takes place post-mortem, as this salmon had been 

 out of the water 36 hours or more before it reached us. In this case 

 the connective tissue has the usual appearance, without the hyaline 



