TIIK < ;ii !:<;. \KINW.K 



87 



or elongated oval bodies, sometimes divided by constrictions 

 into segments. Occasionally, one end of the body is pro- 

 duced into a sort of rostrum, which may be armed with re- 

 curved horny spines. 



In the ordinary Gregaritice, the body presents a denser 

 cortical layer (ectosarc) and a more fluid inner substance 

 (endosarc), in which last the endoplast (nucleus) is imbed- 

 ded. The presence of contractility is manifested merely by 

 slow changes of form, and nutrition appears to be effected by 

 the imbibition of the fluid nutriment, prepared by the organs 

 <>t the animals in which the Gregariuoe are parasitic. There 

 is no contractile vacuole. 



The Gregarince have a peculiar mode of multiplication, 

 sometimes preceded by a process which resembles conju- 

 gation. A single Gregarina (or two which have become 

 applied together) surrounds itself with a structureless cyst. 



Fio. 7. A. Gregarina of the earthworm (after Lieberktihn) ; S. encysted; r. D, 

 contents divided into pseud o-navicellae ; E, F, free pBeudo-navicellae, G, H, tree 

 amoebiform contents of the latter. 



The nucleus disappears, and the protoplasm breaks up (in a 

 manner very similar to that in which the protoplasm of a 



