258 
Sidnev I. Koniliaaser 
to which the staiii is extracted. In favorable cells, correspoiiding to 
tbat of Figiire 55, but seeii in end view (Fig. 56), one can distinguish, 
by its compactness, this deeply staining paii’ from the eighteen ends 
which correspond to nine longitudinally double loops, or to the eighteen 
autosomes of the spermatogouia. 
After the polar arrangement is lost, the loops can still be foUowed 
and counted. Figure 57 shows aU ten loops; the line of union of the 
components of each loop being still clearly visible. The increase in size 
of both cytoplasni and nucleus is noticeable at this stage. The growth 
continues until the beginning of the formation of the tetrads in the late 
leptotene stage, when the maxinmm cell size is reached. As the autosome 
loops elongate and become less distinct, the deeply staining pair also 
increases in size and is more conspicuous (Plate XIX, Figs. 58, 59, 60), 
its halves being again strikingly different from each other; one (x) is a 
solid rod of chromatin, the other (y) a beaded string of chromatin gra- 
nules of various sizes. While the members of this pair are fused together 
at one end only, they are never in intimate contact any where eise, al- 
though generally they ai’e exactly pai'allel. It can haidly be doubted 
that they arise from the pan seen in Figures 48 and 54 (xy) by their end 
to end fusion followed by parallel apposition of the thieads throughout 
their whole length. That the affinity for each other of the two chronioso- 
mes forming this pair is not so great as that displayed by the pairs form- 
ing the autosome loops, is shown by their slowness in becoming parallel, 
by the space between them when parallel, and by their early sepai'ation, 
which has already begun in the stage represented by Figure60(PlateXIX). 
As seen in the study of the spermatogouia (Plate XIX, Figs. 15, 18, 
20—23), there were twenty chromosomes in E. iimtata, not nineteen as 
previously reported by Boeing (’07). This author describes one of the 
nineteen as a large curved a:-chroniosome, which makes its appearance 
in the growth period as a long twisted deeply staining body. That this 
“deeply staining body” represents a pair of chi'omosonies, is shoAvn not 
only by its own structure and origin, but also by the spermatogonial 
counts. It therefore cannot represent an a>chromoscme, but must be 
an allosome pair, differing less from the autosomes in behavior than 
do the idiochroniosonies of the Heteroptera, even where these {Oncopeltus 
fasciatus and Nezara hilaris) are of equal or nearly equal size. These 
are the only paired allosomes so far described in the Homoptera. It can 
not be doubted that they differ from the autosomes and that the halves, 
judging from the amount and character of the chromatin in each of them, 
are not of equal value. Since they lead to the formation of two sorts of 
