1883.J PROF. HUXLEY ON THE OVIDUCTS OF OSMERUS. 133 



"In the Smelts {Stmten), however, there passes from each ovary 

 a band, one edge of which is attached to the dorsal, the other to the 

 abdominal wall, so that, in each lateral half of the abdominal cavity, 

 there is a chamber which receives the eggs when they are detached 

 from the ovary. The two chambers ultimately unite above the anus ; 

 and, in fact, close in front of the place where, in other fishes, the 

 oviduct is situated. 



" Thus the Smelts appear to present a remarkable transition to 

 that structure of the oviduct which alone is met with in the other 

 classes of the Vertebrata. Instead of the oviduct having, as in 

 these, the character of an independent tube, in the Smelts only one 

 half ot It is found, and yet this has united in such a way with the 

 wall of the abdominal cavity that a part of this wall takes the place 

 of the other balf of the oviduct." 



And, further, at page 159 : — 



"That a proper oviduct is absent in the Salmon tribe has already 

 been stated, and also that they possess an analogue of that struc- 

 ture. This consists of a flat, narrow band, which commonly arises 

 at the upper and posterior end of the plate-like ovary, gradually 

 diminishes in v^idth backwards, and finally becomes lost towards the 

 eud of the abdominal cavity. In the Salmon proper it dit-appears 

 upon the air-blauder, opposite the commeucement of the last fifth of 

 the abdominal cavity, in the freshwater Trout on the sides of the 

 intestine not far froi" the anus, in the Coregoni (Maranen) on the 

 intestiue ciose to its end. 



" The transition from this band-like membranous process of the 

 ovaries of the iiigiier Salmonoids to tiie oviduct of most fishes is 

 remarkably exemplified in the Smelts. In these, in fact, a delicate 

 membranous process, a mere fold of the peritoneum, proceeds from 

 the end of each ovary, the upper edge of which is attached to the 

 renal organ, the lower to the wall of the abdomen. In this way a 

 cavity lies behind each ovary, bounded externally b}' the wall of the 

 abdomen, and internally by this band. When the eggs are detached 

 they tall into these cavities, which become narrower behind, and 

 leave the body by a common aperture which lies behind the anus. 

 The end of the intestme lies between the two cavities ; and since the 

 left ovary 1'?=^ far from the posterior end of the abdominal cavity, the 

 singular oviduct which has just been described has, on the left side, 

 a considerable length ; the right oviduct, however, is very short, the 

 right ovary being situated so far back." 



Rathke finally observes (p. 160) that he does not consider the 

 condition of the ovaries in the Salmonoids, Eels, and Lamprevs to 

 represent the lowest condition of these parts in fishes, but rather to 

 result from the subdivision of the reproductive organ into two sepa- 

 rate parts — the one productive, and the other educative. 



1 am not aware that, since Kathke wrote, any one has paid atten- 

 tion to the remarkable arrangement which he describes ; and though 

 I have often intended to look nito the matter myself, it is only lately 

 that I have carried my design into efieci. 



