5 SEX AND HEREDITY 



of a beetle named Blaps, occasionally found in cellars 

 and outhouses in our own neighbourhood, and (2) Plas- 

 modium, the parasite which causes one of the most 

 destructive of human diseases, namely Malaria. 



In the case of Stylorhynchus (Fig. 34), the essentials 

 of the process of syngamy are as before the fusion 



FIG. 34. 



Illustrating the process of syngamy in Stylorhynchus (after 

 Leger). 



$ . Male gamete ; $, female gamete. 



together of two cell-individuals (gametes) to form a single 

 individual (zygote) but in this case the two gametes are 

 no longer exactly alike : one is a rounded motionless 

 creature (i, $) ; the other is somewhat spindle-shaped, 

 one end being prolonged into a powerful flagellum, and 

 swims actively hither and thither, until coming into the 

 neighbourhood of a gamete of the first type it is attracted 



