QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE, 93 
duct being there the first vestige of the uro-genital apparatus 
of tubes, from which all the others appear to bud, or into 
which they are pushed), Balfour and Foster (loc. cit.) main- 
tain that it arises as a ridge at about the thirty-sixth hour, 
projecting from the mass of uncleft mesoblast on the outside 
of the protovertebre into the triangular space covered in by 
epiblast above. This ridge becomes hollow by its cells ac- 
quiring a radiating arrangement around the commencing 
lumen. Waldeyer held that the lumen was formed by the 
closure of two ridges (‘Eierstock und Ei,’ 1870). Romiti 
( Archiv f. Mikroskop. Anat.,’ 1874) describes the Wolffian 
duct as being formed by an involution of the epithelium of 
the pleuro-peritoneal cavity, in the form of a longitudinal 
groove, which speedily closes in, and looses its communica- 
tion with the pleuro-peritoneal cavity. According to Foster 
and Balfour this is certainly the way in which the Wolffian 
duct is formed in Amphibia and osseous Fishes, and this 
makes them receive Romiti’s statements with the greater 
caution. 
Dr. Alex. Schultz, of Strasbourg, in the ‘ Centralblatt’ of 
Oct. 31st, states that he has observed the same facts in 
embryo Torpedoes as those recorded by Semper for Sharks. 
A primitive longitudinal canal—the Miillerian duct or Urnie- 
rengang—is observed, into which a series of funnel-like open- 
ings make their way, so as to connect the long duct at 
intervals with the peritoneal cavity. Each funnel corresponds 
accurately with the limit between two proto-vertebre. 
Schultz differs with Semper as to the male genital duct. 
He declares that this develops directly out of the Miillerian 
duct (Urnierengang) without intervention of the funnel-like 
organs or their continuations. It is not clear from the papers 
above cited what is the precise significance given by various 
authors to the terms Urnierengang, Miillerian duct, Wolffian 
duct. It would be well, in the present state of the question, 
to abandon these terms, and use others which have no implh- 
cation. 
E. Gasser has published, at Frankfort, a graduation thesis 
On the Development of the Allantois, the Miillerian ducts, and 
the Anus. His observations relate to the Chick. He states 
that the Miillerian duct makes its appearance on the third 
day of incubation in the form of a short groove, between the 
already existing Wolffian body and the Hautplatte. This 
closes up and forms a funnel, the narrow end of which grows 
towards the anus. There is never a union of the Miillerian 
duct with the duct from the Wolffian body, at the posterior 
part, as His maintained. 
