198 



GENERAL EMBRYOLOGY 



active than the smaller microgametes, which may be formed in very 

 considerable numbers. Occasionally the gametes differ in form only, 

 as in Dallingeria, where one of the gametes has three flagella, like the 

 vegetative cells, while the other gamete has but one flagellum. In a 



FIG. 104. Micro- and macrogametes of various Protozoa, illustrating various 

 degrees of differentiation. After Doflein, from various authors. /, F, x 562, 

 others X 1125. a, A. Urospora lagidis (Brasil). 6, B. Collozoum inerme 

 (Brandt), c, C. Chlamydomonas braunii (Goroschankin) . d, D. Volvox aureus 

 (Klein), e, E. Cyclosporia caryolytica (with two polar bodies in cytoplasm of E) 

 (Schaudinn). /, F. Orcheobius herpobdella (Kunze). 



few forms such as Monas and many of the Gregarines, the only morpho- 

 logical difference between the gametes is that of size, the microgamete 

 being smaller and somewhat the more active, but not otherwise unlike 



