PLATE 1 
EXPLANATION OF FIGURES 
Spermatogonial division 
A metaphase plate, with ten chromosomes. 
Two cells in metaphase (right and middle), and one in anaphase (left). 
Early telophase. 
4 Late telophase; the nucleus is beginning to resume the appearance of 
‘resting.’ 
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WwW bh 
First spermatocytie division 
5 A ‘resting’ cell, with its chromatin substance in the form of a reticulum. 
6 to 13 Cells in early prophase (lepto-zygotene stage). Rearrangement of 
the reticular chromatin substance into a double spireme is taking place. Figures 
12 and 13 show the polarized condition of the forming double spireme. 
14 and 15 ‘Contraction stage.’ The duality of the spireme is already com- 
pletely established. 
16 to 18 Degenerating cells. 
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