329] STUDIES ON GREGARINES— WATSON 119 



The intestine is the usual seat of infection, although the pyloric 

 caeca are not infrequently found to contain parasites. The latter are 

 generally present in small or moderate numbers, from 1 to 25 per 

 host, and nearly ever cricket examined at this season was parasitized. 

 Sometimes the number per host runs up to one hundred or more, but 

 this is rare. 



The parasites are solitary, never associative in the normal sporont 

 life. The maximum recorded length is 500/x, the maximum width 160/x. 

 The ratio of length protomerite to total length for fifteen specimens is 

 1 :5 to 1 :7. The ratio of width is 1 : 1.3 to 1 : 1.7. The protomerite is 

 slightly wider than high. It is broadly cone-shaped, dilated in the mid- 

 dle and constricted at the septum. The constriction is very conspicu- 

 ous and fairly deep in the adults. There is no papilla at the anterior 

 end. The deutomerite is cylindrical to elongate ellipsoidal, sometimes 

 tapering but always rounded at the end (Figures 218, 221). 



The endocyte is very dense and black in the deutomerite (in trans- 

 mitted light) and pale tan in the protomerite, the two parts being 

 sharply contrasted. Longitudinal striations are easily discernible with 

 the aid of an intra vitam stain or after crushing the body and releasing 

 the dense endocyte (Figure 243). The nucleus is spherical and contains 

 one or two small karyosomes. It is not visible in the dense adults, but is 

 seen in vivo in the younger sporonts and in the trophozoites. 



The epimerite is a large simple spherical hyaline knob set upon a 

 short slender stalk (Figures 224, 227). The sarcocyte is very distinctly 

 visible in contrast to the contiguous endocyte. It is thin and of even 

 width throughout. 



Trophozoites with epimerites are common, both free in the lumen 

 and attached to the cells of the intestine. They are transparent or 

 nearly so. Some individuals are surprisingly large. 



Cysts average 350/^ in over all diameter, the transparent envelope 

 being about 30/i, in thickness when the cyst is new. Dehiscence is by 

 spore ducts from one to twelve or more in number. Spores are extruded 

 from the long ducts in chains. The spores are barrel-shaped and meas- 

 ure 3 by 6/i. 



This species was described by Crawley (1903:45) as Gregarina 

 achetaeahbreviatae Leidy and later as Stenophora erratica. Crawley 

 first considered the species identical with Leidy 's Gregarina achetaeah- 

 breviatae from the same host but later (1907:221) created for it a new 

 species because 



" — at the anterior tip of the protomerite the ectosarc is often thickened to form 

 a low papilla, within which are traces of a pore." 



