76 E. P. CHURCHILL, JR. 



Four mussels were kept in a .005 per cent, fat solution for the 

 several periods of 4, 7, 18 and 24 hours. A small amount of fat 

 was found in the epithelium of the intestine, mantle, gills and 

 foot of the individual of the 4-hour period. None was found in 

 the other parts of the body. About the same amount and dis- 

 tribution of fat was observable in the case of the mussel which 

 had been in the solution for 7 hours. In the animal which was 

 kept in the fat solution for 18 hours a very appreciable quantity 

 of fat was found in regions corresponding to those in which it 

 had been found in the mussels which had remained in the solution 

 for 4 and 7 hours. A small amount was noted in the tissues 

 immediately beneath the epithelium. None was found in the 

 deeper body tissues, a fact which is in striking contrast to the 

 case of the mussel which had been kept in fat solution for 10 

 days. The mussel which had remained in fat solution for 24 

 hours contained a considerable amount of fat in the same parts 

 of the body in which it was found in the cases of the individuals 

 which had remained in the solution for 4, 7, and 18 hours. 

 Even more fat was found in the epithelium of the gills, mantle 

 and foot than in that of the intestine (Figs. 16, 17, 18, 19 and 20, 

 PI. III.). A very small quantity of fat was observable in the 

 liver cells. In certain parts of the foot a moderate amount of 

 fat appeared immediately beneath the epithelium, some of which 

 fat was adhering to the muscle fibers. The fat droplets became 

 progressively less numerous as the tissues were studied to a 

 greater depth within the foot and none were found among the 

 muscle fibers or in the other tissues making up the main central 

 mass of the foot (Fig. 17, PI. III.). The corpuscles, especially 

 those found in the gills, contained fat in many cases. In the 

 gills the crowding of the corpuscles against the bases of the cells 

 of the filaments was marked (Figs. 18 and 19). Every appear- 

 ance was given that the fat was absorbed from the solution by 

 the epithelial cells of the gills and was taken up from them by 

 the corpuscles in some cases and in others thrown directly into 

 the plasma of the blood. Fig. 20, PI. III., shows a portion of the 

 epithelium of the mantle. Fat was seen in the epithelial cells 

 of the side next to the body and for a short distance beneath 

 them but it was not found scattered throughout the deeper parts 



