Zool.— Vol. I.] EISEN—PLASMOCYTES. 49 



there can be no doubt as to the homology of my archosome 

 with his Nebenkern, and also with his wormlike sperma- 

 tozoon. The absence of any differentiation of spheres in 

 his Nebenkern is probably due to the stains used or to the 

 fixatives, my own experience being that Saurefuchsin does 

 not differentiate the archosomal spheres, but on the contrary 

 covers up their finer structure. I am confident that with 

 proper toluidine staining the wormlike spermatozoon of 

 Paludina will show a structure not brought out by the 

 coarser fuchsin; however, enough is shown in Auerbach's 

 figures to satisfy me that we have here a real case of inde- 

 pendence of the archosome, and I am confident that further 

 investigation will show an undoubted homology of the worm- 

 like spermatozoon of Paludina and the plasmocyte of the 

 blood of Batrachoseps. 



At the time I was reviewing the above mentioned mono- 

 graph by Professor Auerbach, my attention was called to a 

 most interesting paper on "The Sexual Phases of Myzos- 

 toma" (Mittheilungen a. d. Zoolog. Station z. Neapel., Bd. 

 12, 1896, Heft. 2), by Dr. Wm. M. Wheeler. 1 In this 

 paper Dr. Wheeler figures certain bodies, living free in the 

 body cavity of Myzostoma, which he describes, provision- 

 ally at least, as parasitic amoeba?, under the name of Amceba 

 myzostomatis. The body of this amoeba is at various places 

 produced into fine points, one of which is seen to penetrate 

 the cytoplasm of the ovum of the Myzostoma. In other re- 

 spects the parasite is entirely external to the ovum. The 

 fine needlelike point of the amoeba pierces the ovum more 

 or less deeply, and always from the side furthest away from 

 the nucleus of the ovum, at least so it appears in the figures. 

 The region of the cytoplasmic part of the ovum in the im- 

 mediate vicinity of the inserted point exhibits a most re- 

 markable radiation: as Dr. Wheeler says, "not unlike an 

 astrosphere at the pole of a karyokinetic spindle." This 



1 1 am under great obligations to my friend Professor Herbert P. Johnson, of the 

 University of California, for having attracted my attention to the remarkable 

 amoeboid bodies described in Dr. Wheeler's paper. 



