152 JAMES ERNEST KINDRED. 



cell membrane and basement membrane in fluid form not as 

 droplets. Having reached the connective tissue the fluid is 

 dispersed in the form of droplets. 



Among the food droplets large numbers of leucocytes can be 

 seen. Most of these leucocytes are in the act of ingesting 

 droplets. The ingested droplets vary in number and in size 

 (Fig- 3)- I n those cells which have ingested large numbers of 

 droplets the cell body is' distended far beyond the normal size 

 of a leucocyte. The cells containing the most droplets are, as a 

 rule, nearer the peritoneal surface of the intestinal wall. During 

 the first stages of ingestion the droplets are smaller than the 

 spherules of the amebocytes, but during the later stages of 

 ingestion, the small droplets coalesce to form larger ones. The 

 color of the droplets all through the first stages of ingestion is 

 greenish and the droplets are apparently unaffected by the stain. 

 As the droplets enlarge they acquire a slight basophilic reaction. 



Cells with typical basophilic spherules are very numerous in 

 the lacunae at the bases of the regions of food ingestion and 

 sometimes are found in the connective tissue meshes among the 

 ingesting leucocytes. Amebocytes with acidophilic spherules, on 

 the other hand, are seldom present in the intestinal wall. 



CONCLUSIONS. 



One phase of this investigation has demonstrated that the 

 tinctorial reactions of the cells of the perivisceral fluid of Arbacia 

 punctatum are identical with those of other echinoids. That is 

 to say, the cytoplasm of the leucocytes is not tinctorially active, 

 the spherules of the amebocytes with colorless spherules are 

 basophilic in reaction, and the spherules of those with red or 

 yellow spherules are acidophilic in reaction. 



The second phase of this investigation reveals what I infer 

 to be a genetic relationship between the leucocytes and the 

 amebocytes with spherules. This inference depends primarily 

 upon the interpretation placed upon the tinctorial reactions of the 

 food droplets ingested by leucocytes in the intestinal wall. My 

 preparations show leucocytes ingesting food droplets. It is also 

 known that the leucocytes contain vacuoles giving an acid 

 reaction to neutral red (Kindred, '21). Hence those cells in 



