PLATE 3 



EXPLANATION OF FIGURES 



35 The plasmosomes and idiochromosomes during the growth period of the 

 first spermatocyte showing formation of spireme threads and their contraction 

 into the prochromosomes. 



36 and 37 Prophase of first spermatocyte showing connected idiochromosomes. 

 38 Metaphase plate of first spermatocyte with idiochromosomes in center. 



c-39 Side view metaphase of first spermatocyte to show dumb-bell-shaped chro- 

 mosomes and their transverse division. Idiochromosomes joined together. 



40 Same as the preceding. 



41, 42, 43, and 44 Side views of dividing first spermatocyte, showing idio- 

 chromosomes during anaphase and telophase. 



45 Oblique view of anaphase of dividing first spermatocyte. Thirty-three 

 chromosomes plus the idiochromosome complex which here shows each idiochro- 

 mosome as bivalent. 



416 



