A Study of Sonic Grcgari)ics 19 



with signs of degeneration, and eight, while showing the chro- 

 matin, have the cytoplasm so broken up that degeneration is evi- 

 dent. Ahowing for two dupHcates in this hst, the total number 

 of degenerates is twenty, a percentage of almost 39 ; eleven 

 showed the sporocysts, so that 21 per cent certainly ripened. The 

 remaining 40 per cent showed the chromatin in such normal ap- 

 pearing cysts that it seems probable that the ripening process was 

 going on, though slowly. The ripening was in a room with a 

 temperature of about i8°C. 



The time required for ripening here is unusually long. Biit- 

 schli (1881) found cysts of Gregarina blattarum ripening at sum- 

 mer temperature in about five days ; Magalhaes ( 1900) . found 

 the same form requiring from four days to a week; Wasielewski 

 (1896) gives fourteen days as a" common ripening period and 

 states that some need over a month; Crawley (1905) finds that 

 ripening occurs in periods varying in dififerent forms from one to 

 thirty days. It is probable that gregarine cysts from the fall spe- 

 cies of Mclanophis ripen very slowly at the low temperatures of 

 winter, perhaps not completing the process before the return of 

 M. jiuicnsis, the probable spring host. This would make the win- 

 ter ripening period something like five or six months. 



Sections show that the sarcocyte has degenerated or condensed. 

 Its constituent parts may take some part in the formation of the 

 cyst covers. In recently formed cysts the partition between the 

 two individuals separates readily along its opposed surfaces under 

 the impact of the microtome knife, but in older cysts the partition 

 shows a distinct lenticular thickening in the middle. The line of 

 separation between the two individuals usually persists externally 

 for a long time. 



Chromatin occurs diffused or as the foci of a network, as Mar- 

 shall (1893) found it in Gregarina blattarum, for most sections. 

 Three sections shoAV clean-cut nucleoli. In one of these, a cyst 

 ripened dry for fifty-five days and in water for twenty-five, no 

 partition is present, the single nucleus is somewhat "flamed" and 

 contains the nucleoli. This is evidently an encystment of an in- 

 dividual gregarine. In another case the partition separates two 

 vacuolated areas, one clear and the other granular. The nuclei. 



167 



