Wilcox. — Spermatogenesis. 



PLATE III. 



Caloptenus fem ur-ruhrum . 



Figs. 105-107. Spermatogonia. 



Fig. 108. Longitudinal section of testicular follicle, a, spermatogonia ; h, growth 

 zone of spermatocytes; c, first division of spermatocytes; d, first stages 

 of spermatids ; e, later stages of spermatids ; f, abortive spermatogonia. 



Fig. 109. Cross-section of vas deferens containing spermatozoa. 



Figs. 110, 111. Spermatocytes in the spirem stage. 



Figs. 112, 113, 117, 118, 122, 12-}. Spermatocytes in the first division. 



Fig. 114. Spermatocyte of the first order before dumb-bell stage of cliromatin. 



Figs. 115, 116. Spermatocytes of the first order in the dumb-bell stage of chromatin. 



Figs. 119-121, 124. Spermatogonia in division. 



Figs. 125, 120, 129. Spermatids just after division of the spermatocytes of tiie 

 second order. 



Fig. 127. Spermatocyte, first division. . 



Fig. 128. Spermatocyte, second division. 



Fig. 130. Spermatocyte before first division. 



Fig. 131. Spermatogonium, polar view of spindle. 



Figs 132-138. Spermatogonia in division. 



