Sex Determination in Phylloxerans and A phids 267 
v 
8 BR ® 
‘€ $s e° r) ® 
C D 2 
A B 
FFig. XVII A-B, nuclei just prior to the formation of the first spermatocyte; C-H, equatorial 
plates of first spermatocytes; [—O, division of same; P, rudimentary cell; Q-W, nuclei prior to second 
spermatocyte; X, Y, B’, C’, equatorial plates of second spermatocytes; Z , A’, rudimentary cells; D’, 
E’, F’, division of second spermatocytes. 
