366 Mr. R. Hill's Contributions to the 



it is remarkable how, iu the Squalidte, the general exhibition of 

 the membrane, from its appearance in the early stages of gesta- 

 tion to its disappearance at an advanced period of foetal life, is 

 the gradual exhibition of the advance from the viviparous to the 

 oviparous character. It progi-esses onward from the Acanthias, 

 through the Galeus to the Scyllium, whose horn-encased eggs are 

 hatched out of the body. Whether the gland of the ventral ap- 

 pendages has the same progressive development, has not been 

 ascertained; but in the season when the male Shark seeks the 

 company of the female, the parietes of its caxdty are turgescent 

 with red blood in those species, particularly the Carcharias, iai 

 which it exists. n 



Having given a description of the male and female Shark, we 

 shall next proceed to give an account of their habits in deep water, 

 and under the influence of air, light, and heat. 



We see that the male, when it has advanced to the condition 

 of a full-grown fish, is subject to a peculiar stimulus of the 

 genital organs. In the more temperate seas, the sexes are 

 excited, as soon as the spring sets in, to seek each othei-'s com- 

 pany. The couplings are frequent, and the female excludes the 

 young at distant intervals of time which coincide with the order 

 in which the ova are successively fecundated. It is said that 

 the same male impregnates twenty females; that there is no 

 constancy in its attachment to a companion; and that chance 

 alone decides its choice of a mate. This remark no doubt is the 

 result of observations made on the Dog-fish, the commonest of 

 the Shark-tribe in the temperate zone ; for no such familiarity 

 with Carcharias can occur in tropical seas, to enable a person to 

 speak of the habits of numbers. Lacepede, writing of the 

 Requin, the common Shark of the Atlantic, says, that about 

 thirty young ones are produced in a season. On our own shores 

 immature Sharks are prodigiously numerous, though larger fish 

 are comparatively scarce. The canoes seldom bring in less than 

 five in each haul of the sein. There are usually several hauled 

 every morning in each fishing village. On such a coast as Old 

 Harbour or Passage Fort, this would give ten or fifteen thousand 

 in the year. For Kingston Harbour alone, taking every place 

 in its circuit, it would make a destruction of from one hundred 

 to one hundred and fifty thousand annually. They are thinned 

 ofi" by a number of voracious fishes. The Cetacean Dolphin 

 pursues them constantly, and as scarce one in a thousand can 

 reach maturity, the annual produce from a single female is much 

 more likely to be a hundred than only thirty*. 



* This calculation seems to give an incredible number, but this is trifling 

 compared with the Bone-dog Shark {Acanthias vulgaris), known on most 

 fishing stations in Europe and America. Mr. Cou,ch says, " It is the most 



