100 JOSE F. NONIDEZ 
chromosomes, respectively. As already mentioned, the normal 
or, perhaps better, the usual condition is that the small chromo- 
somes pass along with the X-chromosome into the same cell. 
How the former distribution is brought about I do not know. 
It is an open question whether or not such cells give rise to fune- 
tional spermatozoa.. If they do, shght numerical variations 
ought to be found in certain individuals. We have ample proofs 
on the viability of individuals with a number of chromosomes 
slightly different from the normal in the species, as furnished 
by the cases in which supernumerary chromosomes occur, and 
also by the remarkable case of non-disjunction of the sex chromo- 
somes in Drosophila (Bridges, ’16). But, in all the individuals 
of Blaps so far studied, the number of chromosomes appears to 
be constant. 
Some of the figures on the dissociation of the complex might 
convey the impression that occasionally the X-chromosome takes 
the place of one of the M-chromosomes and enters one of the 
secondary spermatocytes alone. Without denying this possi- 
bility, on account of the striking numerical variations observed 
here and there, | must emphasize the variable position of the 
X-chromosome with reference to the M-chromosomes. It is 
evident that in some cases this chromosome is not at the apex, - 
but in the free end of one of the arms of the V-shaped complex. 
Therefore the M-chromosome, which appears occupying the apex 
passes alone into one of the spermatoctyes, while the others enter 
the opposite cell. Under identical conditions the normal dis- 
tribution may also take place, the X-chromosome, and the M- 
chromosome to which it is linked, entering the same cell. These 
facts strongly suggest the possibility of a variation in the fiber 
attachment, leading to conditions very different from those de- 
scribed in the metaphase and pointing to an efficient distribution 
of the components of the complex. In teleological language, the 
most important thing here would be, not the relative position of 
these components, but their final distribution, and in order to 
fulfill this end a corresponding variation in the attachment of 
the spindle fibers takes place. 
