288 Chromosomes in the Spermatogenesis of Anasa Tristis 
corner of the group of the eleven chromosomes, and just below the 
upper microchromosome. In Photo. 19 it is the curved chromosome 
on the left periphery of the group. In Photo. 20 it is to the right of 
the lower microchromosome. In Photo. 21 it is nearly in the center of 
the group. In Photo. 22 it is on the left periphery of the group—below 
and to the left of the large cross-shaped chromosome. In Photo. 23 it 
is just below the large cross-shaped chromosome, and in Photo. 24 it is 
on the left periphery of the group, just below and to the left of the upper 
microchromosome. 
There is certainly not the remotest resemblance between this chromo- 
some and chromosome hh of Wilson’s section (Photo. 17), nor is there 
a single chromosome of all the eleven which in the least resembles the 
chromosome fi of Wilson’s section—though there is a likeness between 
some of the other chromosomes of his section and those of our prepa- 
rations. 
Later stages in the development of the eccentric chromosome are 
demonstrated in the photographs of Plate II and when possible we 
shall compare these photographs with Wilson’s and Montgomery’s 
sketches of sections. This is, however, by no means a simple matter, 
for in addition to their omission of many of the stages, the chromosomes 
of their figures show such complete lack of detail that they resemble 
a group of densely-stained nucleoli, nearly all individuality of form 
being omitted or perhaps destroyed by their technique (Text Figs. 1 and 
Ne 
Plate IJ.—In Photos. 1 to 12 the eccentric chromosome can be traced 
through the early prophase to the late prophase or metaphase, where it 
is shown in its characteristic position outside the ring of nine chromo- 
somes. These photographs, which show the transition of the chromo- 
somes from the early prophase (Photo. 1) to the late prophase or 
metaphase (Photos. 12 and 13), demonstrate that during these stages, 
the chromosomes may become smaller and denser, this being due evidently 
to contraction of the chromosomes and not to the giving off of any 
of their substance. In Photo. 1 the eccentric chromosome is on the 
upper periphery of the group and to the right of the large cross- 
shaped chromosome. In Photo. 2, it is just above the center of the 
group, being readily identified by its typical form (two thin parallel 
rods). In Photo. 3 it is on the lower left periphery of the group and 
though somewhat curved, its typical form is not obscured. In Photo. 4 
it is below the group and its form in this preparation is unusual—it is 
a distinct tetrad, as in fact are all the ten large chromosomes, our re- 
