Anomalies in the Genital Organs of Toads. 7a 
ro) 
Many of the ova contain large numbers of yolk spherules which 
have formed, as in normal ova, at the periphery of the cell. In 
some few cases I have found two distinct layers of yolk spherules ; 
one lying at the periphery, the other half-way between the surface 
of the cell and the nucleus (Fig. 24). In eases of this kind it is 
probable that the inner layer of yolk spherules was derived from 
yolk-nuclei which appeared in a ring midway between the nucleus 
and the periphery of the cell and were there transformed directly 
into yolk spherules. I have found one or two cases somewhat similar 
to this occurring in the ovarian ova (King, 708). 
This hermaphroditic toad was killed at the breeding season when 
the germ-cells have become mature and the large ova in the normal 
Bidder’s organ have reached the highest stage in development of which 
they are capable. It seems probable, therefore, that the large cells 
in the rudimentary ovaries have also attained their maximum devel- 
opment, and that they would have undergone rapid degeneration 
and absorption to give place to another generation of similar cells, 
had the individual not been killed. This assumption seems the more 
plausible since a number of the largest ova in the rudimentary 
ovaries already show marked degenerative changes. 
The processes of degeneration occurring in the nuclei of the large 
cell found in these rudimentary ovaries are somewhat different from 
those taking place in the large ova of Bidder’s organ, and they differ 
also from the disintegration processes occurring in mature eggs that 
for some reason have failed to leave the ovary. The first evidence of 
degeneration is the migration of the nucleoli to the centre of the 
nucleus where they lie massed together as shown in Fig. 20. At this 
time ali of the nucleoli are rounded in outline and, with but few excep- 
tions, they stain uniformly black with iron hematoxylin. The chro- 
matin threads can sometimes be seen in the nucleus at this stage, 
although they cannot be found at a later period owing, possibly, to 
the fact that Flemming’s fluid does not fix the chromosomes well in 
cells of this size. The next step in the degeneration of the nucleus 
is shown in Fig. 20. Many of the nucleoli appear vacuolated, others 
stain faintly and are evidently being dissolved. Only that portion 
of the karyoplasm in which the nucleoli lie is uniformly finely 
