PLATE 13 



EXPLANATION OF FIGURES 



Second spermatocyte metaphases. 



626 to c From the individual with the minimum number of atelomitic chromo- 

 somes, seven in spermatogonia (Plate 11, 62a). For first spermatocyte see Plate 

 9, 62. There are four types owing to the presence of the supernumerary as 

 follows : 



6, eleven chromosomes. 



c, eleven chromosomes plus supernume ary. 



d, tweve chromosomes. 



c. twelve chromosomes plus supernumerary. 



636 to e The four classes of second spermatocytes formed by individual 63. 



69 Circotettix lobatus, eleven chromosomes. 



696 Same, ten chromosomes. 



518 



