PLATE 5 



EXPLANATION OF FIGURES 



59 Two anaphase drawings of second spermatocyte from same cell. Sixteen 

 chromosomes in each. 



60 Spermatids from division of eighteen chromosome second spermatocyte. 

 The divided idiochromosomes differ in shape and are darker stained than the 

 autochromosomes. 



61 Young spermatids before the reorganization of nucleus. 



62 Anaphase of second spermatocyte, showing ring-like arrangement of chro- 

 mosomes. 



63 Early formation of nucleus of spermatid. 



64 Spermatid with resting nucleus and nucleolus. 



65 Early spermatid with rod centrosome. 



66 Same as the preceding, showing centrosome with granule at base lying 

 against nuclear membrane. 



67 Same as the preceding. The granule broken off. 



68 Same as the preceding. The granule much enlarged. 



69 Elements of nebenkern from early spermatid. 



70 Spermatid showing division of granule. 



71, 72, and 73 The nebenkern ring from spermatid, showing separation of 

 granules and formation of new body from the nebenkern. 



74 Central part of nebenkern of spermatid, showing rosette form and spindle 

 remains. 



75 Spermatid showing vacuolization of nebenkern border further advanced. 

 Nuclear granules larger and stain darker. 



76 Spermatid showing centrosome applied to nuclear membrane. 



77 and 78 Spermatid showing clear space forming around chromatin of 

 nucleus. Middle-piece anlage present. 



420 



