Abnormalities of Reproductive System found in Frogs. 253 
B. The Accessory Sexual Apparatus. 
It is seen that wherever obvious spermatic tissue is present in a gonad 
vasa efferentia connect it with the adjacent kidney. In case No. 11, three 
of the efferent ducts of the gonad were traced into the ovary also. It would 
seem as though these had been developed in anticipation of the transforma- 
tion of this into a testis. In these cases there is some evidence that the 
development of these ducts is consequent upon the expression of spermatic 
tissue in the gonad, and since the foundation material, out of which they 
are developed, is commonly possessed by both sexes, there is nothing 
remarkable in their adaptation in response to the demand which arises 
when spermatic tissue is developed later than is usual. Their number 
and complexity of pattern is normally subject to considerable variation, 
but roughly in these cases they are proportionate to the amount of spermatic 
tissue present in the gonad. Seminal vesicles were present in every case, 
smaller than those of the average male of the same species and at the 
same time of the year in the cases in which most of the genital tissue was 
ovarian, and equal in every way to those of the typical male, in the 
others, in which a considerable amount of spermatic tissue was present 
in the gonads of the individual. There is a suggestion, therefore, that 
the development of these male organs is proportionate to the amount and 
functional activity of the spermatic tissue in the gonads of the individual. 
The fact that the two vesicles are generally equally developed supports 
the conception that the blood-borne internal secretion of the testes may 
supply the stimulus which evokes their growth. 
The degree of development of the Miillerian ducts varied. In those 
cases in which ovarian tissue constituted the bulk of the gonads, they were 
equal in every way to the functional oviducts of the mature female. In 
those cases in which considerable amounts of ovarian tissue still remained 
in both gonads, though it exhibited evidence of severe degenerative change, 
the ducts were well developed on both sides of the body. In two cases 
in which one gonad was almost entirely testicular (Fics. 7 and 16), the 
Miillerian duct of that side was but weakly developed. 
The conditions found suggest that the degree of development of these 
ducts is decided by two conditions :— 
(1) The time during the development of the individual at which the 
spermatic tissue first makes its appearance ; and 
(2) The extent of the expression of the spermatic tissue, whether it 
appears in both gonads synchronously, or first in one and 
later in the other, 
