Davis. — Spermatogenesis. 



PLATE 6. 



All figures are of Stenohothrus nirtipennis. 



Fig. 83. Stage g, primary spermatocyte. 



Figs. 84, 85. Stage h, primary spermatocyte. The monosome is seen below 



in Figure 85. 

 Figs. 86, 87. Stage i, primary spermatocyte. 

 Figs. 88, 89. Metaphase first maturation division. The figures are drawn 



from successive sections of the same cell, all the chronlosomes 



being shown. The monosome is near the lower pole in Figure 88. 

 Figs. 90, 91. Metaphase of first division. The figures are drawn from 



successive sections of the same cell. The monosome is near the 



upper pole in Figure 91. 

 Fig. 92. Metaphase of first division. The monosome is near the lower pole. 

 Fig. 93. Anaphase of first division. 

 Fig. 94. Late anaphase of first division. 

 Fig. 95. Semiresting stage, secondary spermatocyte. The monosome is 



seen at the upper side of the nucleus. 

 Fig. 96. Metaphase of second division. 

 Fig. 97. Anaphase of second division. 

 Fig. 98. Telophase of second division. 



