SEX STUDIESS | Su 13 
the naked eye, and some show in section in figure 18. There 
is the usual large number of nests of lutear cells in the theca 
interna, as shown in figure A. Some of these lutear cells 
present a feature not seen in any other bird, they contain a large 
number of acidophile granules. That these cells with granules 
are not the interstitial cells can be seen by comparing figures 
A and B. Figure B is a group of interstitial cells from the 
stroma of this same ovary. The interstitial cells are smaller 
and more closely packed with granules. The only difference 
among the cells in figure A is that some are clear and some have 
granules. They are the same as to size and nucleus. The 
number of real interstitial cells is small (fig. C). In various 
parts of the gonad, there are older lutear cells with the yellow 
pigment. Whether these corpora lutea represent discharged 
or atretic follicles it is impossible to decide, as the involution 
process has proceeded beyond the stage where this distinction 
can be made. The microscopical structure together with the 
eross anatomy show 1439 to be a female. 
There is not much choice as to the order in which the next 
three birds shall be described, as the ducts of all three are of 
the female type, and the reproductive organs of all are indiffer- 
ent enough to make it somewhat difficult to sex them. 
The dissection of 1428 is shown in figure 11. The two Wolf- 
fian ducts are easily seen in this photograph, being of consider- 
able size. The bird has a larger coiled oviduct than 1429, and 
a lobulated reproductive organ on the left. This organ has 
a large watery tumor to the left of it, showing that it is also 
in an abnormal physiological condition. It is exceedingly 
difficult to sex this organ. It is largely composed of tubules, 
which radiate toward the periphery from a central connective 
tissue core. But the entire surface looks like an ovarian stroma 
(fig. 19) and all this connective tissue at the periphery and con- 
tinuing down between the tubules contains many masses of 
the lutear cells normally found in the theca interna (figs. 19 ¢ 
and 20 t). The tubules are in some places lined with character- 
istic columnar epithelium cells (fig. 20), but in most the cells 
appear to be breaking down (fig. 19). In the central core of 
