PLATE 6 ' 



EXPLANATION OF FIGURES 



Side views of eight first spermatocyte metaphases, form 'B.' Note the dif- 

 ference in general appearance between plates 2 to 5 and 6 to 9, due to prepon- 

 derance of atelomitic and J-shaped tetrads in former. 



33 Chromosome number 4 (accessory) in two sections. 



38 Chromosome number 10 broken. 



504 



