578 



THE POPULAR SCIENCE MONTHLY 



case of Paramecium, it will be seen that the conditions are entirely 

 different from those which accompany conjugation in the majority of 



Fig. 12 



Protozoa. In the latter fertilization is accomplished by the formation 

 and fusion of gametes or minute simulacra of the adult cells, some being 

 differentiated into microgametes and macrogametes, or male and female. 



