319] 



STUDIES ON GREGARINES— WATSON 



109 



protomerite and deutomerite and is black in transmitted light. The 

 nucleus is not visible in vivo. 



Cephalonts and cysts were not recovered from the host. 



A table of measurements in which all dimensions are given in 

 microns follows: 



Total length association 1110 1110 1080 



Primite 



Length protomerite 100 



Length deutomerite 450 



Width protomerite 130 



Width deutomerite .._ 170 



Total length sporont 550 



Ratio 



length protom. : total length sporont...l :5.5 



width protom.: width deutomerite...l :1.3 

 Satellite 



Length protomerite 70 



Length deutomerite 530 



Width protomerite 130 



Width deutomerite 190 



Total length sporont 560 



Ratio 



length protom. : total length sporont... 1 :8 1 



width protom. : width deutomerite...l :1.5 1 



100 

 450 

 130 

 180 

 550 



1:5.5 

 1:1.4 



130 

 430 

 130 

 210 

 560 



:4.3 

 :1.6 



100 

 440 

 110 

 180 

 540 



1:5.4 

 1:1.7 



80 

 440 

 130 

 170 

 520 



:6.5 

 :1.3 



1050 



90 

 410 

 110 

 170 

 500 



1:5.5 

 1:1.5 



70 

 480 

 120 

 180 

 550 



1:8 

 1:1.5 



This species and the Old World Gregarina ilattarum Sieb. of Blatta 

 orientalis are differentiated as follows: 



Shape 



Posterior end satellite 



Sarcocyte 



Shape protomerite of 

 satellite 



G. hlattarum 

 Irregularly cylindrical 



Not well rounded, 

 often pointed 

 Very thick 



Flattened, wider at 

 base than elsewhere 



1.7 times as wide as 

 at top, 2.5 times as 

 wide as high 



G. illinensis 

 Very regularly cylin- 

 drical 

 Well rounded always 



Thin except in proto- 

 merite 



But slightly flattened, 

 as wide at base as at 

 top, 1.5 times as wide 

 as high 



