700 SURGEON F. DAY ON NEW INDIAN FISHES. [Nov. 4, 



diameter. Inside the mouths of several of the males of the Arius 

 subrostratus, C. & V., A. gagora, H. B., A. sumatranus, Bennett, 

 and Osteogeniosus militaris, Linn., were from 15 to 20 eggs; and it 

 was evidently some of these which had been dropped into the boats 

 and baskets. 



On examining the eggs, some were in an early stage of development, 

 whilst in others the eyes of the embryo were very distinct, even the 

 young could be perceived moving about. In the mouth of one of 

 these fishes was a hatched fry, with the yolk-bag still adherent ; and 

 on cutting open other eggs it became evident that in a very short 

 time the little ones would have emerged. These eggs filled the ca- 

 vity of the mouth, and extended down as far as the branchiae. 



On dissecting a number of these specimens, there was an entire 

 absence of food in the intestinal canal. The fishermen asserted that 

 these adult fishes, which averaged about 11 or 12 inches in length, 

 invariably carried about the eggs in their mouths until they were 

 hatched. Every one of these were males; and the proportion cap- 

 tured was five to every female *. 



Next, the females came under examination. On tracing up the 

 ovisacs it appeared that very large numbers of eggs existed in them, 

 but not all of the same size. On the part furthest removed from 

 the outlet the eggs were of full size, and about 50 in number, whilst 

 other batches of much smaller size existed, evidently to take the 

 place in due time of the larger ones when they had been deposited. 



The full-sized eggs were each attached to the inside of the ovisac 

 by a pedicle of varying length, distinctly supplied with blood-vessels 

 of a considerable size. No cicatrices could be detected showing that 

 anv eggs had burst into the cavity of the abdomen ; and it would 

 appear probable that they are extruded in the usual way, which idea 

 is strengthened by the peculiar formation of the ventral fins. 



On looking at the conformation of the ventral fins of the males 

 and the females, one is at once struck at the difference which exists 

 in the two sexes t. The ventrals in the males are not enlarged ; but 

 they are very considerably so in the females, reaching well over some 

 of the first of the anal rays. They are also thickened by a deposit 

 of fat, whilst the innermost ray has a large pad of fatty matter at- 

 tached to its posterior margin. These fins can be expanded into a 

 cup-like surface, the use of which is probably to receive the eggs as 

 extruded. 



Perhaps the eggs as laid in batches are received into this recep- 

 tacle formed by the ventral and anal fins, and may be here vivified 

 by the male, who then removes them in his mouth, where they re- 

 main until hatched. Although the males at this interesting period 

 appear to fast, the females do not do so, their intestines being found 

 to be replete with food, doubtless a necessity for the due production 

 of their eggs. 



* This is curious, as differing in the usual proportion of the sexes. In the 

 C'firpea palasah, C. & V., I found just the reverse obtained. 



t The comparative length of ventral fins in fishes of the above genera is not 

 any guide to species, but merely to sexes. 



