264 American Fisheries Society 



transparent striated border which is more or less charac- 

 teristic of intestinal epithelium in general. The basal por- 

 tions of the epithelial cells have a relatively small quantity 

 of fat in medium sized droplets. The loading of the cells 

 is great in the distal ends and slight in the basal ends, as is 

 readily seen in numerous preparations. In the connective 

 tissue stroma, between the two folds of the epithelium, fat 

 is present in relatively small amount and in the form of 

 comparatively large droplets. In contrast with this stage 

 in absorption is that in which the free ends of the epithelial 

 cells are practically free of fat. while the basal portions 

 of the cells are crowded full of extremely finelv divided fat. 

 The submucous zone, or stroma, has a relatively large 

 amount of fat in small droplets. Considering the two show- 

 ings together one cannot escape the conclusion that we have 

 to deal here with two stages of fat absorption rather than 

 with a problem of fat storage. 



In material taken from the sea fish, as shown in the 

 above cases, one has neither choice nor accurate knowledge 

 of the stage of feeding represented by a given individual. 

 However, I attempted on the basis of the amount and stage 

 of digestion of the food present in the stomach and intestine, 

 to select salmon representing possible stages in the process 

 of fat absorption. A series of three salmon were procured, 

 all with considerable food in the alimentary tract — one with 

 slight, one with medium, and one with advanced stage of 

 liquefaction of this food. A microscopic examination of 

 the pyloric cceca of this series tended, with some degree of 

 uncertainty, to confirm the assumption made in their selec- 

 tion, namely, that they would show increasing amounts of 

 fat in the mucous epithelial cells as digestion and absorption 

 proceeded. 



While these observations were in progress, at the invi- 

 tation of Dr. Charles H. Gilbert, of Stanford University, I 

 visited the Santa Clara County trout hatchery at Brook- 

 dale, Cal., that I might secure samples of young sal- 

 mon for comparative histological purposes. The station had. 



