THÉEL, THE AMOEBOCYTES BY ECHINODERMS. 17 



schwach gelb gefärbte Zellen. Es ist dies das einzige mir zur 

 Beobachtiing gekommene Beispiel gefärbter Zellen im Inhalt 

 der Leibeshöhle. » This statement seems to ha ve escaped the 

 attention of Ray Lankester (1872)^ when he published his 

 contribution to the knowledge of hsemoglobin, in which pa- 

 per he enumerates some cases where hsemoglobin is present 

 in special corpuscles of invertebrates. 



HowELL (1885)^, who examined the fluid of the coe- 

 lomic cavity and water-vascular system in a Cucumaria {plan- 

 ci?), relätes: »the red corpuscles exhibit no tendency to adhere 

 to one another, though they become entrapped in the mas- 

 ses of fused white corpuscles», and further on he says — pro- 

 bably with regard to another holothuria (Thyone gemmata?) 

 — : »whose perivisceral liquid is in some cases of a bright 

 red colour. Examination of this liquid and of the contents 

 of the water-vascular system showed that the colouring mat- 

 ter has most of the properties of hsemoglobin, though cer- 

 tain differences in its chemical reaction have led me to be- 

 lieve that it is not identical with the heemoglobin of verte- 

 brate blood. The water-vascular system and the body-cavi- 

 ty contain, besides colourless amoeboid corpuscles, a large 

 number of oval, nucleated, biconvex blood discs of a påle red 

 colour. » 



On pages 635 and 636 Cuénot (1891)^ says in his »Études 

 sur le sang et les glandes lymphatiques dans la Serie animale»: 

 »Quelques espéces ont en outre des hématies {Cucumaria 

 planci, Thyone gemmata y Thyone aurantiaca), parfois assez 

 nombreuses pour colorer le sang en ruge ou en rose {Cucu- 

 maria planci)». In the subsequent relation of the blood- 

 corpuscles Cuénot gives us the following notice which may 

 be quoted on account of its singularity: »Ce qui est tres in- 

 teressant, c'est qu'au repos, la membrane hématique émet 

 de fin pseudopodes protoplasmiques, plus ou moins nom- 

 breux; Thématie en elle-méme ne change pas de form, les 

 pseudopodes, d'ailleurs peu actifs, émanant simplement de 

 la membrane limitante». 



^ Proceedings of Royal Soc. of London. Vol. 21, pp. 71 — 81. London 

 1872.^ 



- John Hopkins L^niversity Circulars. No. 43, pp. 4 — 5. Baltimore 

 1885. 



^ Archives de zool. expérimentale. Sér. II, Torne 19, Paris 1891. 



Arkiv för zoologi. Bd 13. N:o 25. 2 



