124 MARGARET REED LEWIS AND WM. REES B. ROBERTSON. 



PLATE V. 



FIG. 38. J. G. Young spermatid, centrosome divided. Nebenkern granules. 

 Leitz Binoc. 4b X 1/12 lens. 



FIGS. 39, 40. Unstained. Young spermatid. Neutral red granules. Thread- 

 like appearance in the nebenkern. Zeiss 6 oc. 2 mm. lens. 



FIGS. 41, 42. J. G. Nebenkern dividing is now granular. Neutral red 

 granules. Leitz 4b X 1/12 lens. 



FIG. 43. Unstained. Nebenkern divided. Zeiss 6 oc. 2 mm. lens. 



FIG. 44. Unstained. Nebenkern sacs with the centrosome close to the nucleus. 

 Neutral red granules. Zeiss 6 oc. 2 mm. lens. 



FIG. 45. Unstained nebenkern sacs are slightly elongated. Zeiss 6 oc. 2 mm. 

 lens. 



FIG. 46. J. G. Nebenkern sacs elongated. Axial filament. Double middle 

 piece body. Neutral red granules. Zeiss 6 oc. 2 mm. lens. 



FIGS. 47, 48. J. G. The tail failed to develop but the mitochondria elongated 

 and formed the double thread as usual, although the double thread is wound round 

 and round within the cell. Leitz Binoc. 4bXi/i2 lens. 



FIG. 49. N. R. The cytoplasm of the tail is gathered into nodes and the 

 neutral red granules appear. The mitochondria is now in the form of two homo- 

 genous long threads. Zeiss 6 oc. 2 mm. lens. 



FIGS. 50, 51. J. G. Later stages of the spermatozoon. 



