A Study of Some Grcgarincs 5 



protomerite flattened at its union with the cyhndrical deutomerite, 

 the latter rounding off rather abruptly at the posterior end 

 (fig. 8). 



This gregarine is quite active, especially as regards locomotion. 

 Gregarines lying motionless in the intestinal fluids on a slide, if 

 brought into the light of the Abbe condenser, would remain quiet 

 for a few moments and then glide away, displaying a pronounced 

 negative heliotropism under what seemed an irritating stimulus. 

 An interesting variation of this occurred when a young and trans- 

 -parent specimen was brought over the condenser and remained 

 quiet; the entocyte, however, rapidly clouded up, finally becom- 

 ing quite opaque. Gregarines would occasionally travel away 

 from the body content, but usually turned back from the pure salt 

 solution farther out, as though under chemotactic or physical 

 stimulus. 



A gregarine with the protomerite partly withdrawn into the 

 deutomerite,— a condition common in Stenophora julipnsiUi, but 

 rare in this gregarine,— was on one occasion observed traveling 

 backwards against a diffusion current by a sort of jerking move"^ 

 ment of the entire body. Jerking movements have been noted as 

 occurring under certain circumstances by Crawley (1905), and in 

 the same paper he notes a gregarine which eVen advances by 

 leaps. 



Change of shape, both by flexion and by symmetrical variations 

 of body outline, is quite common, though the flexion is more de- 

 liberate than that of Grcgarina hlattanim and never carried to 

 the same extent. In change of bod)- outline I have seen speci- 

 mens with a pronouncedly convex deutomerite outline gradually 

 bring in the walls of the body until the outline was concave. 



Although the shape of the gregarine is that previously stated, 

 with the protomerite subglobular and body cylindrical, it should 

 be said that when the animal is on a hard surface, such as a glass 

 slide, the portion of the protomerite and deutomerite which Is in 

 contact with this surface flattens out, and specimens killed under 

 such conditions will frequently retain the flattening, which can 

 be seen as the gregarines float about in the fluid reagents. So 

 far as I can judge, any part of the body surface will "serve as a 



153 



