THÉEL, THE AMOEBOCYTES BY ECHINODERMS. 11 



»amoebocytes with spherules» (— hvita kulamoebocyter), 

 which probably have löst in vitality and been devoured — 

 ef. text-fig. 2: 1 and 2. 



It may be questionable, whether I am light in my sup- 

 position that the cells in question really have been devoured, 

 or CuÉNOT, wlio observed the same phenomenon, though lie 

 interpreted it in quite a different manner. He namely thought 

 himself entitled to draw the conclusion from his observation, 

 that he had to do with the evolution of the »corpuscule muri- 

 forme». For on page 636^ he says: »Mais Tamibocyte ne reste 

 pas longtemps dans cet état, son seule röle consistant en Faccu- 

 mulation de produits nutritifs: on voit, en ef fet, ce former dans 

 son prot oplasma des granules incolores, assez gros, d'aspect 

 adipeux, qui offrent aux divers réactifs tous les caractéres 

 des albumoides; ces granules deviennent de jolus en plus nom- 

 breux et finissent par remplir la cellule qui émet toujours 

 des j)seudopodes. Quand le développement est complet, Tami- 



bocyte s'est transformé en corpuscule muriforme ^». 



As regards myself , I cannot accept the interpretation of Cuénot. 



Intermingled with the amoebocytes, small, hyaline, pyri- 

 form corpuscles occur, which evidently are devoid of motive 

 faculty. Such spermatozoa-like corpuscles are rather common 

 in the coelomic cavity as well as in the polian vesicle of Tliyone 

 fusus and they reach a length of up to 38 [x. Rarely, I fancied 

 I observed one or two fine threads running out from the head- 

 portion of them — ef. text-figure 2: 4. Beside these pyriform 

 corpuscles, also fusiform, hyaline ones are to be met with in 

 the body cavity, and above all in the jDolian vesicle. Both 

 of them seem to be in want of a nueleus and may probably 

 be looked upon as löst elements of tissues. The fusiform ones 

 bear a close resemblanee to those corpuscles which I have 

 found in Labidoplax and described further on as dubious cry- 

 stals. 



Cucumaria elongata and hyndmani. 



In these two species the number of plasma-amoebocytes 

 is very reduced. I leave it undecided whether this poverty 

 bears any relation to the richness of red blood- corpuscles, 

 which fill up the body-cavity, the reciprocal proportion between 

 them being as about one to ten. Consequently, the syncytia 



' Arch. de Zool. Expér., Ser. 2, T. 10. Pciris 1801. 



