FORMATION OF SPORES AND GERMS. 199 



host, and have lived for sometimes weeks or months in the water, 

 while in ordinary cases they are formed soon after the encapsulation, 

 or at least while yet inside the host. The shape of spore, so charac- 

 teristic of the Gregarines and Psorosperm-saccules, is here replaced 

 by a simpler spherical or ovoid form. 



Along with the spore-formation there occurs simultaneously the 

 development of the embryonic body, which appears throughout to be 

 in the form of a hyaline sickle-shaped rod. Adjoining these, the 

 usual granular body ("nucleus de reliquat") is present with equal 

 constancy. The number of rods varies, but is generally from six to 

 eight (Fig. 100, D-F '; Fig. 101, D, JE). Coccidium oviforme always 

 forms only a single rod, 1 which lies on the granular mass (Fig. 102, (7). 



When these structures attain development in the body of their 

 host, then, according to Kloss and Eimer, one can observe a distinct 

 movement, which, under favourable circumstances, may be watched for 

 hours, and is associated with a manifold change of form (Fig. 100, 6r). 

 When they pass into the quiescent state they assume a more or less 

 compressed, sometimes almost spherical form, although they usually 

 retain a slightly curved shape. Kloss calls the movement " leech-like," 

 and sometimes compares it with the creeping motion of a sluggish 

 Euglena. 



In this contracted state these rods are in size and appearance 

 so thoroughly identical with the scarcely nucleated youngest stage of 

 the parasites, that (considering the contemporaneous presence and 

 the different number of stages) one can hardly be mistaken in con- 

 necting the latter directly with the mobile germs, and crediting 

 the forms in question with continuous multiplication. 



Of course this applies only to what may be called the " viviparous " 

 species. When the formation of germs takes place outside the host, 

 as in Coccidium oviforme, then the appearance of immense numbers 

 must of course be due to often repeated introduction. 



Whether structures somewhat similar to the above, the so-called 

 "Miescher's tubes" (Synchytrium Miescherianum^opf), are to be referred 

 to the class Sporozoa, is more doubtful, since no phenomena of move- 

 ment have yet been observed in any developmental stage. Since, 

 however, they are usually ranked with the Psorosperm-saccules, in 

 accordance with a decision which I was the first to give, 2 and have 

 indeed many points of resemblance with these forms, a brief discussion 

 of their nature is necessary. We must confess that our knowledge of 



1 [Balbiani (loc. cit., p. 105) believes that he has proved that the sickle-shaped bodies 

 are double also in Coccidium oviforme, but that the two portions lie closely pressed to- 

 gether. R. L.] 



- This work, first German ed., Bd. i., p. 240. 



