THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



YoL. IT. 



New Yokk, June, 1881, 



No. 6. 



On a Parasitic Structure Found 



in Eulbranchipus Yernalis, 



Yerrill. 



BY DR. CARL F. GISSLER. 



Numerous specimens of Eubran- 

 chipus were found infested with small, 

 roundish corpuscles. They were 

 densely packed together in several 

 layers, and filled out the entire body, 

 post-abdomen, claspers, anterior an- 

 tennae and the branchipeds. They 

 were whitish disks visible to the 

 naked eye ; they measured 45/^-50/" 

 in diameter, and about 15/'' in thick- 

 ness. In alcoholic specimens their 

 interior constituted a granular, coag- 

 ulated plasm with three or four lar- 

 ger, central groups encircling a finer 

 granulation. I found but two disks 

 with an entirely black centre, and 

 many without any cellular aggrega- 

 tion in the centre. 



The cyst, or capsule in which they 

 were enclosed, is a dense and struc- 

 tureless cuticle ; a face-view of these 

 disks exhibits five distinct rings of 

 the cuticle ; but after having pre- 

 pared them in different mediums, I 

 found that those rings were but an 

 optical illusion, due to the elevated 

 margin of the disk. 



Whether this endoparasite is of 

 vegetable or animal origin is hard to 

 say ; it may be an encysted infus- 

 orium or one of the encysted, devel- 

 opmental stages of a fungus. 



Dr. O. Biitschli figures and de- 

 scribes* a parasitic structure with 

 four distinct concentric walls and ra- 



* Archiv fur Naturgeschichte. 38 Jahr- 

 gang, I, Heft, 1872, p. 248, Taf. IX, fig. 3. 



dial lines arranged between the rings. 

 He found it in the posterior portion 

 of the chylus-tract of Porcellio 

 scaber. This, to my knowledge, is 

 the only parasitic form similar to the 

 one in question. 



Eubra7ichipus verna- 

 lis (Fig. 23) is a beauti- 

 ful, branchiopod crus- 

 tacean, a sort of fresh- 

 water shrimp, and oc- 

 curs during the winter 

 months only.* In the 

 Winter of 1879-80 I 

 fed sixteen frogs with 

 infected Eubranchi- 

 pics, and kept them in 

 a damp cage to exa- 

 mine their intestines, 

 etc., after some two 

 or three mouths ; but 

 they all died after 

 about fifteen or seven- 

 teen days, and nothing 

 extraordinary could 

 be found at the post 

 mortem examination. 

 Although not successful in the single 

 experiment, it is possible that in 

 spring, when all individuals of Eu- 

 branchipus die and their bodies decay 

 at the bottom of ponds, the parasite 

 becomes free during the process of 

 decaying and enters another cycle of 

 life, probably as an amoeboid or fun- 

 goid organism. Some individuals of 

 this second generation may become 

 imbedded in ice, and like many par- 

 asitic helminths, may propagate only 



*See American Naturalist, 1878, p. 

 1880, p. 531 ; 1881, pp. 136 and 280. 

 entijic American, April gth, 188 1. 



Sci- 



