\ 



THEEL, THE AMOEBOCYTES BY ECHINODERMS. 3 



As already alliidecl to, three accoiints of the leucocytes 

 of invertebrated animals have been published lately.^ Con- 

 sidering that in more than one respect they touch the subject 

 for my researches, I may be allowed to begin my report with 

 some quotations of their relations, and to draw some paral- 

 lels between our respective results. 



On page 42 of their interesting studies »in crustacean blood » 

 Tait and Gunn say: »In Astacus as in Ligia there are three 

 well-marked types of blood corpuscles, viz. explosive cor- 

 puscles, hyaline thigmocytes, and granular thigmocytes — ef. 

 Tait (1918). As the last alone possess the power of amoeboid 

 movement, we shall here ref er to them as 'amoebocytes', 

 restricting the term »thigmocytes» to cells of the second- 

 named variety, since they show the phenomenon of thigmo- 

 taxis in most striking fashion. » 



First of all, I must confess with regard to the explosive 

 corpuscles, that I ne ver saw anything like them in an echino- 

 derm. 



The granular thigmocytes of Tait or amoebocytes of Tait 

 and Gtjnn on the contrary are evidently identical with my 

 »kulamoebocyter » (amoebocytes with spherules) described 

 and figured by me — ef. Parech. mil., pp. 30 — 39. 



As to the hyaline thigmocytes, they bear a close reseni- 

 blance to the discoidal plasma-amoebocytes described and 

 figured by me — ef. Ast. rub. pp. 5 — 8, pl. 1, figs. 4, 13; and 

 Parech. mil., pp. 23 — 24, pl. 1, fig. 2 and pl. 4, figs. 19 — 21. 

 As may be understood from the relations and figures in the 

 papers above quoted, my idea of the discoidal j)lasma-amoe- 

 bocytes is in all respects that expressed by Tait with regard 

 to the hyaline thigmocytes. On page 3 he says, namely: 



» After a stage of fairly rapid commotion, during 



which processes of the cytoplasm are protruded and withdrawn 

 again, the cell begins to spread on the surface of the glass. 

 This process is accompanied by marked vacuolisation of the 



holm 1919. — Considering that the swedish text dcmands repeated quotations 

 and declarations, I eniploy the abbreviations : Ast. rub. and Parech. mil. 

 ' ^ John Tait. Capillaiy phenomena observed in blood cells — Quart. 



Journal of experimental physiology. Vol. XII. No. 1. London 1918; pp. 

 1 — 33; with 6 figures in text. Tait and J. D. Gunn. The blood of Astacus 

 fluviatilis: A study in crustacean blood. with special reference to coagula- 

 tion and phagocytosis. — Ibid. pp. 35 — 80; with 11 figures in text and 3 pla- 

 tes. Edwin S. Goodrich. The pseudopodia of the leucocj-tes of inverte- 

 brates — Quart. Journ. of Microsc. Science. Vol. 04, Part 1. October 1919; 

 pp. 19 — 26; with plates 1 and 2. 



