1076 
SCANDINAVIAN FISHES. 
kidney (the Wolffian body) is separated in the males 
from the posterior part, and is applied, as an epidi- 
dymis, to the anterior part of each testis, receiving 
the efferent duct thereof. 
In the structure of the generative organs the Elas- 
mobranchs are even more closely approximated than 
the Chondrosteans to the higher vertebrates. These 
organs are generally more restricted in extent, whence 
it naturally results that the offspring is far less nu- 
merous than that of the Teleosts. The efferent duct 
(vas deferens, tig. 301, o) of the male organs (n) passes, 
as iu the higher vertebrates, first through an epididy- 
mis. Before opening into the cloaca, it widens into a 
dilatation (seminal vesicle, p), the posterior extremity 
of which is applied to the corresponding part of the 
seminal vesicle on the other side of the body, and then 
finds outlet, in common with the other seminal vesicle 
their slimy secretion. A large gland of this kind is 
situated on the under side of the ventral fins. In most 
cases the said organs are besides furnished at the tip 
with cards of teeth or with spines. 
The copulation between the sexes that is practised 
with the aid of these organs by the Sharks has been 
observed in the case of the Nurse Hound ( Scylliorliinus 
stellaris ) by Bolau at the Hamburg Aquarium, and is 
illustrated by the appended figure (302). Of the copu- 
lation of the Rays Hollberg writes * 6 : “During the 
season of propagation they repair to the surface of the 
sea and, for the purpose of depositing their eggs, to 
the shores. At these times they are taken with the 
harpoon. The female is frequently attended by several 
males, who endeavour by lifting and tossing her with 
their snouts to turn her over on her back. The first 
to succeed in this applies and presses his ventral side 
Fig. 302. Male Nurse Hound clasping the female during copulation. After Bolau, Zeitschr. f. wiss. Zoo]., Bd. XXXV, p. 322. 
and the ureters, into a special cloaca ( k , the urogenital 
cloaca, Moreau, Hist. Nat. Poiss. Fr., tome I, fig. 26, 
p. 246), which projects on the wall of the anal cloaca 
in the form of a papilla (r) only requiring the erectile 
tissue to represent a true penis. In the Chimaeras the 
urogenital aperture of the males lies externally on the 
ventral side, at the anterior extremity of an oblong 
and compressed, but posteriorly tumid protuberance 
behind the vent. 
The external copulatory organs of the males we 
have mentioned above. The most important, the so- 
called pterygopodia of Petri", consisting of the trans- 
formed hindmost radialia of the ventral fins ( metapte- 
rygium in Gegenbaur; fig. 301, ?; fig. 295, ptpd), are 
composed of several parts and furnished with a longi- 
tudinal channel, into which several glands discharge 
so closely to hers that, if only one of them be har- 
pooned, both may be drawn out of the water without- 
being parted.” On the occasion described by Bolau 
the right pterygopodium of the male was inserted into 
the sexual aperture of the female. The male flung his 
tail upwards and forwards along the right side of her 
body and bent his own in the opposite direction, though 
with the dorsal side under, so that the top of his head 
pressed his tail to the back of the female above her 
pectoral fins. In the last-mentioned circumstance we 
may perhaps find a clue to an explanation of the man- 
ner in which the male Chimaeras employ the mobile 
prehensory organ situated on their forehead. The co- 
pulation of the Chimaeras has never been observed; but 
as the mouths of the two oviducts, which open in the 
females of these fishes beside each other and externally, 
a Zeitschr. wiss. Zool., Bd. XXX, p. 296. 
6 Gbgs Wett., Witt. Samli. N. Handl., Ill Delen (1819), p. 16. 
