576 



BIOLOGY OF THE PROTOZOA 



generations by division when they were k)st and reversion to the 

 cmidatmn type occurred, presumably during a period of endomixis. 

 In Hke manner we may account for the amicronucleate races of 

 many ciHates (Hance, Moody, Dawson, Woodruff, etc.), the amicro- 



A^ 



BB 



AB 



CAB 



I'-AD 



FAB 



Fig. 236. — Chlamijdomonas and Mendelism. A, one species of Chlamydomonas; 

 B, a second species; A' gamete of A; B' gamete of B; .4^, union of gametes of type 

 A; SB, union of gametes of type B; AB, union of gamete of A with gamete of B; 



CAA, cyst formed by union of A gametes; CBB, cyst formed by union of B gametes; 



CAB, cysts formed by union of gamete.s from A and B; F:A, one of the four products 

 of the cyst CAB, and like A; FiB, one, like B; F2AB, two individuals of the four 

 with combination of characters of A and B. (After Pascher.) 



