86 JOSE F. NONIDEZ 
duration, if we may judge from the considerable number of cysts 
showing such cells. 
b. Prochromosome stage. In this stage (figs. 67 to 70) the chro- 
matin appears in the form of condensed bodies located at the 
periphery of the nucleus in close contact with the nuclear mem- 
brane; hence in optical section the center of the nucleus is de- 
prived of chromatin (fig. 67, cell to the right). The number of 
massive bodies, which I formerly called ‘cromosomas prelepto- 
ténicos’ (since from each of them a leptotene thread arises), 
agrees with the diploid number, as already stated in my second 
paper (715, p. 157). Reexamination has proved the correctness 
of this assumption. In some cells it is very difficult to be sure 
of their exact number, but even so we can be almost certain that 
it seldom exceeds or falls short of the diploid number. Thus, in 
the cells represented in figure 70, in which the prochromosomes 
were drawn from the same cell, thirty-six dense bodies occur. 
This slight increase may be due either to one of the less dense 
masses being nothing but residual chromatin or to one chromo- 
some being cut into two, as drawings c and d are from different 
sections. The large chromosomes of the complex can be dis- 
tinguished in most of the cells, a description of them being 
given later. 
The process by which the prochromosomes arise is worthy of 
mention. The scattered chromatin granules gather in certain 
places (fig. 66) and, upon further condensation, form the prochro- 
mosomes. Although these resemble very much the chromosomes 
of the metaphase in the spermatogonial mitoses, no threads take 
part in their formation; hence we cannot speak of a true pro- 
phase, since the difference between the two processes is obvious. 
I would suggest that this process might well be called a ‘pseudo- 
prophase,’ since the dense chromosomes arise from chromatin 
masses without passing through the normal stages of spireme 
chromosomes. An early stage of this process is represented in 
figure 66. The cell to the left in figure 67, which represents a 
polar view of a spermatocyte, shows prochromosomes of irregular 
outline which precede the denser bodies. The condensation, 
however, never goes so far as to produce the chromosomes with 
smooth outlines characteristic of mitosis. 
