198 



SPOROZOA. 



and, vice versa, true worms have sometimes (by Eobin) been regarded 

 as Psorosperms. 



FIG. 101. Coccidia from the kidneys of the garden snail A, inside a cell, still with- 

 out a capsule ; , C, encapsuled with Psorosperms inside ; D and E, Psorosperms with 

 germs, in E, in the act of exit (after Kloss). 



So long as these creatures are destitute of a capsule, they appear 

 as membraneless cells with a distinct nucleus. In this stage, they 

 are usually found inside cells, especially epithelial cells, which they 

 gradually cause to swell up in consequence of their growth, and fin- 

 ally destroy by their exit, which usually occurs after the encystation. 

 The spores are formed from the granular contents of the Coccidium, 

 for by this name we shall henceforth designate the so-called " egg- 

 shaped Psorosperms." They are sometimes few in number, but some- 

 times many, and they are occasionally very numerous. The former 

 case is described by Eimer 1 in the form observed by him in the 



intestinal epithelium of the mouse 

 (Eimeria, Schn., Fig. 100). The 

 other case is exhibited by the 

 Coccidia of the Mollusca, e.y., Helix 

 (Klossia, Schn., Fig. 101), or, stiU 

 better, by those of the cuttle-fish 

 (Benedenia, Schn.), which are also 

 infested by these parasites. 2 In 

 Coccidium oviforme (Fig. 102), which 

 is of special interest to us, there are, 

 as far as my observations go, always 

 four spores, which are provided as usual with a comparatively thin 

 shell. They only develop after the Coccidia have left the body of the 



1 ' ' Ueber die ei- oder kugelformigen sog. Psorospermien der Wirbelthiere : " Wlirz- 

 burg, 1870. 



2 The cells grow before the formation of spores to a size of above 2 mm. See obser- 

 vations of Eberth, Zeitschr. f. wiss. Zool., Bd. xi., p. 397, 1862; and Aim<* Schneider, 

 Archiv. d. zool. exjrfr., t. iv., p. 40, 1875. 



FIG. 102. Coccidium oviforme from 

 the liver of the rabbit. In there are 

 Psorosperms in the interior. 



