A STUDY OF THE GENETIC RELATIONSHIPS OF 



THE "AMEBOCYTES WITH SPHERULES" 



IN ARBACIA. 



JAMES ERNEST KINDRED, 

 UNIVERSITY OF VIRGINIA MEDICAL SCHOOL. 



The pioneer work of Geddes (1880) marks the beginning of the 

 study of the cellular elements in the perivisceral fluid of echinoids 

 by means of modern methods. He was the first to recognize 

 the different types of cells, and his classification has been the 

 basis of all subsequent studies. In recent papers I have reviewed 

 the work of those who have studied the reactions of these cells 

 in the living condition both in the Echinoidea and Echinoderms 

 in general (Kindred, '21 and '24). In both of these papers my 

 own investigations have been limited to the functional reactions 

 of the leucocytes, with only incidental remarks as to the "amebo- 

 cytes with spherules." From my observations I have concluded 

 that the leucocytes are the most generalized cells of the peri- 

 visceral fluid and that they are highly phagocytic, thrombogenic 

 and scleroblastic. The "amebocytes with spherules" apparently 

 carry on none of these functions. To be sure, they cling to the 

 clot when it is formed by the thrombogenic leucocytes, but their 

 part is passive. Various investigators have sought to find out 

 where the amebocytes with spherules arise and what they do. 

 Thus far no unequivocal evidence has been presented regarding 

 function, nor have specific places of origin been recorded for 

 these cells. 



Attempts to locate the source of origin of the amebocytes 

 with spherules have led to the applications of blood stains to 

 smears and sections, with a resulting classification of the cells 

 by their tinctorial reactions. St. Hilaire (1897) was one of the 

 first to use these stains successfully and he classifies the cellular 

 elements of the perivisceral fluid of the echinoids by their re- 

 spective tinctorial reactions as follows: a, small leucocytes with 

 neutrophilic granules; b, larger leucocytes devoid of granules, 

 but having one or more nuclei; c, amebocytes with basophilic 



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