PLATE 13 



EXPLANATION OF FIGURES 



(Tettigidea parvipennis) 

 111 to 118 First spermatocyte divisions. Full number of chromosomes in 

 each cell. Figures 115, 118, containing the deficient tetrad no. 4, are from same 

 animal as figures 104, 105, 107 to 110. Note inequality of the no. 4's. 



304 



