237] STUDIES ON GREGARINES WATSON 27 



PART II 

 MORPHOLOGY OF GREGARINES 



MORPHOLOGY OF THE SPORONTS 



The structural characteristics of the Gregarines have been de- 

 scribed by many writers, including Delage and Herouard (1896), 

 Biitschli (1882), Minchin (1903, 1912), Doflein (1911), and others. 

 For this reason I have not attempted to describe the general morphology 

 of the group but rather to state facts of form and structure which I have 

 observed in the two families under observation, viz., the Stenophoridae 

 and the Gregarinidae. 



The Stenophoridae 



All of the species of this family are solitary. In all gregarines 

 which reproduce sexually, the union of two sporonts is necessary but in 

 the Stenophoridae this intimate association lasts only while the cyst is 

 being made and not, as in some families, during the greater part of the 

 sporont life. The cyst is probably formed quickly and this union very 

 brief ; no sporonts were seen in the process of cyst formation. 



One characteristic of almost all the described Stenophoridae is the 

 great length of the deutomerite as compared with the protomerite. The 

 ratio is seldom less than 10 :1 and is often as high as 30 :1. 



The protomerite is not constant in shape ; it is, however, generally 

 more or less conical, rounded at the apex, either as a simple cone (Fig. 

 7) or constricted or dilated slightly halfway from apex to base (Figs. 14, 

 16, etc.) ; there is generally, but not always, a small papilla at the ante- 

 rior end (Fig. 24). The epimerite, which is superimposed upon the pro- 

 tomerite of the cephalont, contains some endoplaSm which is continuous 

 with that of the protomerite through the narrow neck connecting epi- 

 merite and protomerite. At the apex of the protomerite of the sporont, 

 i. e., an individual which has lost its epimerite, the epicyte is very thin 

 and the endocyte reaches nearly to the top. When the epicyte of the 

 sporont upon the slide is ruptured, this rupture takes place at the apex 

 and is accompanied by an extrusion of protoplasm at this point ; the en- 

 docyte breaks first at its weakest place and in this family the apex of 

 the protomerite is the weakest point. The thinness of the ectoplasm at 



