7C 



GUIDE TO THE STUDY' 



3. Gametocytes. — Two similar individuals become associated, 

 and though remaining perfectly distinct from one another, secrete 

 about themselves a common envelope, or cyst. 



4. Gametes. — The nucleus of each gametocyte breaks up into 

 a large number of nuclei. These become arranged around the 

 periphery of the gametocytes, and about each nucleus there 

 is cut off a little of the protoplasm of the mother cell. This 



<e 



Fig. 24. — The gregarine parasites of the meal worm, Tenebrio molitor. 1-4, 

 Gregarina cuneata; 2, conjugating individuals; 3, gametocytes encysted; 4, 

 diagram of spore formation. In a, the gametes formed by the gametocytes are 

 fusing to form sporoblasts, in b and c, the spores are maturing. 5, Gregarina 

 polymorpha; 6, Gregarina steini. (After Berndt.) 



nucleated mass of protoplasm is now known as a gamete, or sexual 

 element. A large number of these gametes are formed, but a 

 portion of the original cell remains as residual protoplasm, or 

 "Restkorper." Study these points in prepared sections through 

 infested seminal vesicles. 



5. Sporoblasts. — The gametes now pass from one cell to the 

 other and conjugate in pairs to form rounded sporoblasts. 

 The nuclei fuse and the sporoblasts become oval and form a 

 spore. 



