PLATE 2 



EXPLANATION OF FIGURES 



8, 9 and 10 Primary spermatocyte, prophase, white. 



11, 12, 13, 14, 15, 16 Primary spermatocyte, metaphase plates, white, show- 

 ing 12 chromosomes. In figures 13 and 14 chromosomes Ui and a 2 are the halves 

 of a divided chromosome. In figure 16 the m chromosome is seen from the end 

 and therefore presents a round profile. 



16 



