A study of the Chromosomes in three species of Pseudocüccus, 
53 
feature, and adds to the probability that the chromosome groups in the 
spermatid correspond to the groups with similar properties in the earlier 
stages. 
Maturation of the Egg. 
No detailed account of the processes of maturation in the egg will 
be given here. Suffice it to say that the diploid nümber of ten chromo- 
somes is reduced to five by pseudoreduction. These five bodies are typical 
tetrads and appear in no way different from tetrads seen in many other 
insects. It is evident therefore that the chromosomes of the female do 
not follow the anomalous process witnessed in the meiotic prophase of 
the male. The mere fact that the haploid number of tetrads is formed 
would alone indicate that the diploid number is comprised of five pairs 
of homologous chromosomes (lig. 53). 
The evidence is obviously insufficient to determine whether the 
female is homozygous for the massed or for the loose group of chromo- 
somes. The failure of the chromosomes in the cells of the female to show 
any massing is not at all an indication of the fact that the spermatozoa 
carrying the loose group are female producing. All such exceptional 
behavior may very well disappear in the presence of the homozygous mate 
of each chromosome, so that the massing evinced in the heterozygous 
state may entirely vanish in the homozygous condition. The correlation 
between sex and the two classes of spermatozoa is therefore not clear. 
Somatic Cells. 
As was mentioned before beginning a description of the maturation, 
the somatic or diploid number of chromosomes in both sexes is ten. As 
usual in developing insects mitotic figures are plentiful in limb buds 
and nervous tissue. The relations of chromosomal conditions to sex are 
determined with little difficulty in later instars of these insects, when the 
gonads are easily recognized. In the earlier instars this relation could 
however not be determined, because neither external nor internal sex 
differentiations could then be found. Chromosome counts were made at 
all stages, adults, various instars, gastrulae, blastulae, and finally in 
nuclei that had not yet reached the periphery of the egg to begin the 
formation of the blastula. There is no room for doubt that ten is the 
normal number (fig. 46 and 49). 
Mention must be made however of certain cells which are frequently 
found during early cleavage stages. These are always several times as 
large as the normal cells at this stage, and contain a larger number of 
