306 



HEREDITY IN THE PROTOZOA 



phrya, and in a few other forms, a similar reduction 

 in the number of the chromosomes has been ob- 

 served. It would seem more probable that we 



Fig. 72.— Two species of Chlamydomonas, A and B. A A and BB, 

 conjugation cysts of .4 and B respectively. AB, hybrid cyst, a, b, ba, 

 ab, types that' develop from hybrid cysts. (After Pascher.) 



must look for reduction before nuclear interchange 

 rather tlian after that event. Even then it has by 

 no means been shown that reduction here means 

 segregation, as in the higher forms, for the value 



