THE MEIOTIC PHENOMENA IN BLAPS 83 
In other cases the distribution of the euchromosomes is quite 
irregular, the number of chromosomes in the secondary spermato- 
cytes showing a surprising variation. I wish merely to emphasize 
this fact without attempting to give its explanation, since posi- 
tive facts concerning the irregularities of distribution are lacking 
at present. 
B. The secondary spermatocytes and the second maturation mi- 
tosis. At the end of the anaphase of the first mitosis the chromo- 
somes become crowded in the poles of the spindle. When the 
daughter cells separate they become looser and are disposed near 
the periphery of a vacuole-like nucleus, without losing their dense 
appearance, although they become a little ragged in outline. By 
this time the spindle of the second division has appeared and 
soon all the chromosomes enter in the metaphase. 
In the latter two large chromosomes of the X-complex, slightly 
elongated and quite separated from each other, can be recognized 
in about half of the cells, while the other half has only one such 
chromosome (figs. 56 and 58). The small chromosomes are no 
longer distinguishable from the euchromosomes. 
The numerical variation already referred to 1s very conspicuous 
at this time. Figure 59 shows a metaphase of a spermatocyte 
lacking the X-chromosome in which seventeen chromosomes 
occur. This number may be explained on the assumption that 
both small chromosomes passed to the cell without the X-chro- 
mosome, as suggested by figure 54, f. 
Corresponding variations occur in spermatocytes with the X- 
chromosome, where the normal number may be decreased by 
one or two (fig. 57). There is always the possibility in this case 
that one or both small chromosomes may be still fused with the 
X-chromosome and do not appear as separate individuals, but 
the increase in the number of chromosomes in the spermatocytes 
of the other kind clearly shows that irregularities certainly occur. 
The division of the chromosomes takes place in the same way 
as in the spermatogonial mitoses, namely, the chromosomes split 
lengthwise and the halves thus produced are distributed among 
the spermatids (figs. 60 to 63). The latter no longer show con- 
densed chromosomes and all appear alike despite the differences 
