PLATE 5 
EXPLANATION OF FIGURES 
Secondary spermatocyte—Continued 
49 Secondary spermatocyte metaphase—twelve chromosomes. 
50 and 51 Secondary spermatocyte metaphases—ten chromosomes. 
52 A typical secondary spermatocyte metaphase spindle, side view. 
53 and 54 Early anaphases. 
55 Later anaphase. 
56 and 57. Telophases. 
58 An exceptional telophase. 
59 Late telophase showing the reconstruction of the two daughter-cells. 
Metamorphosis of the spermatids 
60 Early spermatid showing loosening of nuclear content and also first 
appearance of the supposed mitochondria in the cytoplasm. 
60 to 63 Development of the ‘mitochondrial mass’ and elongation of the 
cytoplasm. Condensation of chromatin to form definite chromatin bodies 
characteristic of the spermatid nucleus. 
63 <A very typical stage at the conclusion of the formation of the mitochon- 
drial mass. The nucleus at its maximum size showing indications of elongation. 
476 
