INTRODUCTION. XXllI 



pouch, is now understood. The supposed hermaphroditism 

 of the Lampreys has been disproved by various modern ob- 

 servers. 



At the season for depositing the spawn, which varies with 

 almost every genus, some species repair to the gravelly shal- 

 lows of rivers, and others to the sandy bays of the sea. 

 This movement is called by some fishermen, " going to hill, 

 or roading ;" other species resort to bunches of weeds. In 

 many instances, when ready to deposit her spawn, a female is 

 accompanied by two males, one on each side, — a provision of 

 nature which seems intended to secure the impregnation of the 

 largest quantity of ova, and the range of the influence of the 

 male fluid is enormously increased by diffusion in water. The 

 adhesive nature of the surface of each egg supplies the means 

 of attachment to any of the various substances near which it 

 may happen to be left ; and the time required for the appear- 

 ance of the young fish is very variable, depending upon the 

 species, the season, and its temperature. The young fish is 

 first apparent as a line wound round the central vitelline por- 

 tion of the egg, and ultimately escapes by rupturing the 

 external capsule with its tail. 



Considerable attachment is often exhibited between the 

 parent fish. Mr. Jesse relates that he once caught a female 

 Pike during the spawning season, and nothing could drive 

 the male away from the spot at which the female disappeared, 

 whom he had followed to the very edge of the water. In 

 some species this attachment is not confined to the season of 

 spawning. A person who had kept two small fishes together 

 in a glass vessel, gave one of them away ; the other refused 

 to eat, and showed evident symptoms of unhappiness till his 

 companion was restored to him. Some few species show also 

 an attachment to their young, and even watch and defend 

 their own spawn. I shall confine myself to a notice of two 



