30 
DR. H. GADOW ON THE CLOACA AND ON THE 
IV. On the presence of Muellerian Ducts in the Males and of Wolffian Ducts in 
the Females of young Crocodilia. (Figs. 6 and 7.) 
Rathke, in his ‘ Untersuchungen liber die Entwickelung und den Korperbau der 
Krokodile,’ p. 191, said that he was unable, from the embryo of Alligator sclerops, to 
ascertain if the canal running along the Wolfftan body was a Muellerian duct or 
not. He was doubtful about the sex of his embryo. 
In a male specimen of Alligator mississipiensis, of a total length of 25 centims., I 
found that the canal, which crosses the vas deferens ventrally and runs along the 
lateral side of the testis, was slightly rounded off at its upper end and seemed to be 
still open, although no bristle could be made to pass through it. This whole 
Muellerian duct was considerably raised above the level of the Wolffian body and 
duct, and was attached all along its length to a very thin and pigmentless peritoneal 
fold. 
In another male specimen, of a total length of 33 centims., only the smallest trace 
of a remnant of the Muellerian duct could be made out on the upper and lower 
ends, whilst the middle portion had already become obliterated. This remnant of the 
duct was no longer prominent, but was imbedded in the same peritoneal fold as the 
vas deferens. 
Female Alligator, total length 29 centims.—The ovary was still quite smooth on its 
surface ; along its lateral edge ran, closely imbedded in it, a light-coloured string, 
which could be distinctly followed between the ureter and the oviduct into the cloacal 
wall. Its upper or cephalic end projected a little beyond the anterior end of the 
parovarium, and was attached to a peritoneal fold like in the males. This is 
undoubtedly the remnant of the Wolffian duct. Laterally from the latter, fastened 
on to a loose peritoneal fold, ran the oviduct and opened into the cloaca a little 
ventrally from the Wolffian duct. 
In the Chelonia the persistence of these ducts has been described and figured by 
Van Wijhe. Fig. 10 shows the remnant of the Muellerian ducts in a full-grown 
male specimen of Testudo grceca. In the adult male Hatteria no trace could be found. 
General Conclusions. 
The want of an intromittent copulatory organ is in the various Vertebrata met in 
very different ways. The fundamental difference between the Selachian pterygopodia 
and any other type of copulatory organs is plainly indicated by the nerve supply, and 
wherever in the Amniota skeletal muscles enter into the service of copulation they 
have become, as shown above (cf pp. 10-14), secondarily attached to the true penes long 
after the latter had been developed from the walls of the alimentary canal. 
The first indication of an intromittent organ in the Amphibia , according to 
Wiedersheim, is a small unpaired papilla on the dorsal wall of the anal or vestibular 
