38 CLASS XIV. 



we find a disposition which in the invertebrate animals is normal, 

 but in the vertebrates does not occur elsewhere, namely that the 

 oviduct is an immediate continuation of the ovary. The two ovi- 

 ducts afterwards meet in a single canal which opens in front of the 

 urethra behind the anus in a small groove, sometimes on a papilla. 

 In other fishes (the eels, the salmons, the Cyclostomes) the ovary 

 consists of an elongated lamina, which is attached to the spinal 

 column by a duplicature of peritoneum, and has many projecting 

 folds ; oviducts are not present ; the eggs developed in these folds 

 are detached when ripe, fall into the cavity of the abdomen, and 

 escape by one or two ventral apertures 1 . In the Plagiostomes and 

 in Chimcera the ovaries are much smaller than in the rest of the 

 fishes ; they lie in the anterior part of the abdominal cavity near the 

 liver, and form bunches as in birds ; whilst some eggs on the surface 

 are more developed, others as smaller granules lie concealed in the 

 stroma. Here there are always two oviducts, even when there is 

 only one ovary. These have a common opening near to or in front 

 of the ovaries, and are by no means immediately connected with 

 them as in the bony fishes. They are very long, provided internally 

 with longitudinal folds, and become wider at the lower part. Above 

 the widening a glandular tissue is situated which surrounds the 

 oviduct as an annular swelling ; it is more developed in those which 

 are oviparous, and consists of many coecal tubes, laid close toge- 

 ther, which open into the oviduct 2 . In the viviparous sharks the 

 inferior wider part of the oviduct may be named uterus, which thus 

 is double, as in the marsupial animals and the ornithorhynchus in 

 the class of mammals. 



The testes (in the bony fishes named milt] are in the male in- 

 dividuals placed in the same situation as that occupied by the ovary 

 in the females. They are larger in this class than in any other 

 vertebrate animals, and the secretion of sperma is as abundant as 

 the eggs are numerous in the ovarium. On the inside of each of 



1 See a figure of the ovarium of the salmon in CARUS Tabulae anatom. comparativam 

 illustrantes, ~Fa.sc. v. Tab. iv. fig. vn. ; of Petromyzon marinus in Catalogue of the Series 

 of compar. Anatomy in the Museum of the Royal College of Surgeons, iv. PL 59; of the 

 eel, ibid. PL 60, and in HoHNBAUM-HoRNSCHUCH Diss. inaug. de Anguittarum Sexu 

 et Generatione. Grijphise, 1842, 4to. 



2 In the rays J. MUELLER has figured this part in his great work, Depenitiori 

 glandularum structura, Tab. n. figs. 14, 15. 



