Anomalies in the Genital Organs of Toads. 169 
at a very early period in the life history of the individual, as in a 
normal toad the cells which develop into Bidder’s organ begin to 
show characteristics which distinguish them from the other germ- 
cells when a tadpole is about two weeks old. 
Sections show that each ovary contains a well defined central 
cavity which is lined by epithelial cells, and that the structure 
of the ovarian wall is the same in each case. In both ovaries the 
great majority of the ova are practically of the same size and 
in about the same stage of development. It is not possible, there- 
fore, to trace the various stages in the growth of the cells or to dis- 
cover any apparent reason for their unusual mode of development. 
With but a few exceptions the cells in both ovaries have developed 
uniformly along the same lines, and those in the upper part of each 
ovary bear no more resemblance to the cells which are typical of 
Bidder’s crgan than do the ones lying more posteriorly which were 
derived, presumably, from primordial germ-cells belonging to the 
sex-gland proper. 
The smaller ova, which usually le at the periphery of the ovaries, 
are rounded in outline, and they have an average diameter of 0.14 
mm. As a rule, the cytoplasm of these cells appears uniformly 
granular, although sometimes it contains yolk nuclei, as shown in 
Fig. 19, Y. N. The nuclei are round, or slightly oval, and they 
measure about 0.08 mm. in diameter; with but few exceptions, all 
of them are in the early post-synizesis stage of development (Fig. 
22). I can detect nothing in the structure of the great majority of 
these small cells that would in any way serve to distinguish them 
from normal young odcytes of the same size. 
In some few cases the smaller cells of these rudimentary ovaries 
exhibit all of the characteristics of the young ova normally found in 
Bidder’s organ. A section of a cell of this type is shown in Fig. 19. 
The nucleus contains a number of nucleoli of various sizes and 
chromatin threads which are composed of a series of deeply stain- 
ing, rounded granules. Two of the larger nucleoli show degenerative 
changes that are similar to those taking place in the large nucleoli 
of the cells of Bidder’s organ which are beginning to disintegrate. 
The body of the cell contains a number of finely granular masses, 
