AN EXTRA DYAD AND EXTRA TETRAD IN CAMNULA 407 
Should non-disjunction of a pair of supernumeraries occur in a 
first spermatocyte cell containing three extra dyads, these two 
additional classes are possible: 
lle+3s 
Ile+2+3s8 
F. Summary of observations on the atypical complexes 
Inconsistencies in the chromosome count within each of five 
individuals are due to the presence of supernumeraries. These 
elements are all apparently genetically related. The extra dyads 
are, in fact, homologues in size, form, and behavior. The super- 
numerary tetrads are formed by the synapsis of a pair of these 
homologous dyads. 
Within the same individual, but in different follicles, the super- 
numerary may be absent in some complexes, present in an 
unpaired condition in some, paired in others, and present in tripli- 
cate in still others. But with the doubtful exception of one com- 
plex in twenty-two spermatogonial cysts, and one complex in 
fifty-two first spermatocyte cysts, the counts are consistent 
for the cyst. With these two exceptions the chromosome num- 
ber seems to be consistent, too, for the follicle, prior to the sec- 
ond spermatocyte generation.» When the extra element is 
unpaired in the first spermatocytes, it behaves precociously like 
the accessory in the late prophase, but shows no tendency to 
synapse with the latter. In the anaphase, it usually passes un- 
divided to one pole, segregating freely with respect to the acces- 
sory. Occasionally the unpaired supernumerary divides in the 
first spermatocyte mitosis. When it does not divide in the first 
mitosis, it divides in the second; conversely, if it divides in the 
first it passes undivided into one daughter cell in the second 
mitosis. When the supernumerary element is paired in the 
first spermatocytes, it exhibits no marked differential behavior 
>It must be admitted, however, that the evidence for an unvarying chromo- 
somal organization for the follicle is not as good as the evidence for such an organi- 
zation in the cyst. For though counts were obtained in seventy-six follicles, in 
only fifteen of these were counts secured in two or more cysts. 
