INTESTINAL COCCIDIA OF THE MOUSE. 219. 



sperm, others, in whose granular contents were embedded varying 

 numbers of clear shining bodies, of about the size of the smallest 

 amoeboid cells. These were found both in the cysts with diffuse 

 contents and in those in which the contents had been retracted from 

 the wall. 



In a subsequent investigation similar stages were also found in the 

 intestine. And further, it was proved that the shining bodies not only 

 multiplied at the expense of the granular mass, but were also changed 

 into sickle-shaped Gregarines, which were surrounded by a membrane 

 originating in the outer surface of the granular ball (Fig. 113, B, C), 

 and which issued from the Psorosperm capsule in this envelope. 

 Already very decided movements could be observed in the young 

 Gregarines, which pushed against one another in the most varied way 

 within the common covering. Sometimes the movements of the 

 isolated animals were to be seen, as above described. They manifested 

 themselves sometimes as contractions, in consequence of which the 

 sickle-shaped structures became " apparently rod -like bodies with 

 terminal balls," and thus assumed a shape in which they perfectly 

 agreed with the rod-like germs of the common Coccidia. Between the 

 Gregarines there was often to be seen a spherical remnant of the 

 original granular mass inside the enveloping vesicle. 



FIG. 113. Coccidia from the intestine of the domestic mouse. 

 A , Inside an epithelial cell, still without capsule ; B and C, Encapsuled 

 forms, with Psorosperms and germs ; D-P, Isolated Psorosperms ; G, 

 Amoeboid brood (after Eimer.) 



There can be no doubt that the enveloping vesicle in the above 

 case is to be regarded as a real Psorosperm, which produces a con- 

 siderable number of rod-like or sickle-shaped germs, but itself origi- 

 nates singly within the " encapsuled Gregarine." Since the formation 

 of spores and germs takes place, as in the so-called Klossia and 

 Benedenia (p. 108), within tke body of the host, the whole develop- 

 ment of the parasite progresses in continuous succession, 1 and there 



1 It is a striking fact that Eimer observed in Psorospermice preserved in chromic acid 

 solution not the above developmental process, but a peculiar segmentation of the granular 

 contents, in consequence of which three,, four, six, and probably even twelve granular balls 

 were fonned under the capsular membranes. Besides these, there also appeared on 

 several occasions, sickle -shaped, shining structures which agreed with the young Gre- 

 garines, except in the absence of vital phenomena (loc. cit., p. 15). 



