408 E. p. CHURCHILL, JR. 



method, stained with Sudan III and mounted in glycerin. In 

 some cases the soap solution was stained by dissolving Sudan 

 III in it to the point of saturation. Sections of mussels which 

 had been kept in such solutions were mounted directly after 

 cutting. 



A method of attacking the question of the absorption of pro- 

 tein was much more difficult to devise. Egg albumin was chosen 

 as the most convenient protein with which to work. The white 

 of one egg was stirred into 300 cc. of water and the mixture 

 filtered. The soluble albumin passed through the filter leaving 

 the insoluble globulin behind. (The presence of albumin in 

 the filtrate could be demonstrated by the formation of a white 

 precipitate on the addition of alcohol.) 50 to 100 cc. of the 

 filtrate were used in 5000 cc. of water to make the solutions in 

 which the mussels were kept. Some experiments were continued 

 for considerable periods of time, thirty to sixty days, and his- 

 tological evidence sought of differences in the condition of the 

 cells of those individuals which had been in the solutions and 

 of the control mussels. As the latter, being in filtered water, 

 received little food it was thought that evidence of starvation 

 might be detected by the appearance of the cells. In other cases 

 the experiments were continued only a few days, the tissues of 

 the mussels were fixed in absolute alcohol or other fixing fluids 

 and sectioned in paraffin. These were studied both stained 

 and unstained. Efforts were made to find a specific stain for 

 the albumin. Cowdry ('14) has found that Janus green, be- 

 sides staining ixiitochondria, stains albumin in the living cell. 

 This fact was made use of and mussels were kept in solutions 

 of albumin stained with Janus green. Sections of such indivi- 

 duals were made by the freezing method and mounted in gly- 

 cerin. The paraffin method failed with such sections as the 

 stain is washed out very readily by the alcohols. It was neces- 

 sary to study the sections mounted in glycerin within the course 

 of a day or two as the stain is also removed by the glycerin in 

 a short time. 



Soluble starch was made by boiling and weak solutions were 

 used in which to keep the mussels. Sections of such mussels 



