HEREDITY 



313 



SPERM A TO GENESIS 



DIVISION PERIOD 



GROWTH PERIOD 



SYNAPSIS 



IsT MATURATION DIVISION 



CHROMOSOMES REDUCED 

 TO HAPLOID NUMBER. 



^NO MATURATION DIVISION 



PRIMORDIAL GERM CELL 



{DIPLOID CHROMOSOME 

 NUMBER) 



SPERMATOGONIA 



SPERMATOCYTE 1 



SPERMATOCYTE H 



SPERMATIDS 



SPERM A TOZOA 



FiG, 201. — Diagram of the maturation of spermatozoa. Note the -two types of 

 sperms, one with and one without an X chromosome. One of each type is introduced 

 in Fig. 203. For convenience the Y chromosome is omitted. 



