
No. 428.] THE ANATOMY OF A DOUBLE CALF. 6r1 
The genital organs show the same relations as the renal ` 
system. There are four testes: two are related to the two kid- 
neys of one body and the other two to those of the other. 
These four testes are, however, paired in the calf not with 
reference to their individual bodies, but with reference to the 
compound. Two, as already mentioned, have descended: they 
are the right of the right body and the left of the left; we 
may call them the two outer testes. The two inner testes also 
carry out the symmetry, both remaining in their primitive 
position beside the kidney. These testes all reach the exterior 
by means of ducts which have the same relation as do those 
of the corresponding kidney. Those of the outer testes cross 
the ureters from the outer kidneys and enter a glandular mass 
(seminal vesicles?) in the wall of the posterior bladder. The 
two inner vasa deferentia run down and attach to the anterior 
bladder, passing as normally to the posterior surface. 
The entire urogenital system thus follows the same law of 
symmetry of the homologous parts as we have seen in the 
other systems of the animal. This is the more interesting in 
this case, for in regulating the relations of the ducts from the 
organs the law comes into conflict with the symmetries of the 
two individuals and replaces it. This is evidence of the pres- 
ence of a deeper law of regulation, and indicates the “ fission 
theory " (Hektoen and Riesman, '01) of origin for the monster 
rather than the “ union theory." 
The limits of this article do not permit an extensive notice 
of the literature of teratology ; a list of writers consulted is 
given at the close. Dr. Fisher (66) gives a figure of a calf 
much like this one externally, — a case of *'diplocephalus 
tetrabrachius tripus," — but the supplementary hind foot is 
ventral and anterior, indicating a difference in the mode of 
union of the pelvic bones. No account of the anatomy is 
given. He mentions that it was dissected by Dr. Wyman, 
but I have not been able to get any information of that dissec- 
tion or its results. The case belongs in the line of double 
formations, which begins at the minimum with doubling of 
digits, runs through every stage of double formation of hands, 
arms, and other parts, of whole regions (as the head and trunk), 
