92 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 
Fishes and Amphibia, seems to us to lead to the confirmation 
of Professor Gegenbaur’s view, and we must look for some 
evidence on the subject of greater weight than what Professor 
Semper has at present advanced, before we can acquiesce in 
his controversial attitude. In a second paper in ‘ Central- 
blatt,’ Nov. 7th, Professor Semper announces a still more 
important discovery, to wit, that these segmental organs, or 
rather the funncl-like mouths which establish a segmental 
character for the Wolffian bodies, can be easily detected in 
many adult Elasmobranchs, e.g. in the genera Scymuus and 
Squatina, also in Spinax, Centrophorus, Acanthias, Hexan- 
chus, Pristiurus, Scyllium. In Squatina they are of large 
size and observable with the naked eye in fresh specimens. 
In his first communication Professor Semper, whilst holding 
the female genital duct to be a distinct secondary structure 
unconnected with the Wolffian segmental organs, was yet 
inclined to believe that the male genital duct took its rise in 
a modification of the funnel-like segmental organs. ‘This he 
now declares to be erroneous, and inclines to the view that 
the common genito-urinary duct of the male is a new struc- 
ture. He finds in young males, and even in some adults, a 
remnant of a tube with expanded internal opening, cor- 
responding to the female genital duct. This either persists 
in a rudimentary state or disappears entirely ; it is therefore 
clear, that the male genital duct is not precisely the same part 
as is the female genital duct in these fishes, since the male 
possesses both. In fact, as far as we can understand Professor 
Semper’s statements, there is strong similarity with the 
disposition of these parts which prevails in the Amphibia, 
the primitive Miller’s duct or original longitudinal canal 
of the primordial renal organ remaining in the female as 
oviduct whilst aborting in the male, and in both sexes a new 
duct develops, connecting the posterior end of the Miller’s 
duct with the mass of the renal body developed out of the 
segmental funnels and their continuations. ‘This duct, by a 
connection of part of the segment-funnels with the testis (as 
epididymis) becomes both genital and urinary in the male. 
Without illustration and fuller explanation, it is not possible 
to arrive at a clear apprehension of Professor Semper’s facts ; 
but it is obvious that he has entered upon a most important 
research (already, we must repeat, broached by Mr. Balfour), 
the full details of which promise to be of exceeding interest 
for students of vertebrate morphology. 
With regard to the bird’s Wolffian duct itself (the appear- 
ance of which in the Chick precedes that of the Miillerian duct, 
though in Anamnia the reverse is the case, the Miillerian 
