INTRODUCTION. XXV11 



influence. If this solution of the problem be the true one, 

 it points at once to what perhaps may be effected after a 

 few experiments, namely, the artificial fecundation of the 

 roe, the drying of that roe, (or of other roe naturally impreg- 

 nated,) sufficiently to prevent decomposition, and its possible 

 transportation to, and vivification in, distant countries. 



The growth of young fish is rapid in proportion to the size 

 of the parent fish, or the ultimate size attained by the species. 

 They appear to be liable to occasional malformation ; an in- 

 stance is figured, vol. ii. page 108, and others of the same 

 kind have been seen, where the upper jaw is deficient in the 

 requisite length. Hervey is said to have been the first who 

 observed that most irregularities in human structure were to 

 be found in the lower animals, and modern physiologists have 

 shown that various gradations of structure permanent in the 

 lower animals are successively assumed by those of higher 

 organization in their passage towards their ultimate develope- 

 ment. These usually transitory conditions sometimes become 

 permanent, and constitute monstrosities. The most frequent 

 malformation in the human subject is that which is usually 

 termed the hare-lip ; the divided lip, and imperfectly closed 

 palate, representing the state of these parts in some species of 

 mammalia of a lower grade of organization than man. In the 

 case of the malformations in fishes here alluded to, the defi- 

 ciency appears to have arisen from an arrest of the formative 

 process at that point in which the shortened state of the 

 upper jaw resembles the rounded upper part of the mouth in 

 the Lampreys, a grade in structure preceding that of the bony 

 fishes. 



The unclosed state of the bones of the head in the human 

 infant, which are not firmly united till some months after 

 birth, is a permanent condition of the cranium in some rep- 

 tiles and fishes, as noticed and figured at page 431. 



Wounds in fishes heal rapidly ; and they appear to have 



