324 FISHES. 



ferent orders of fishes, for these have been mentioned in 

 the proper place in the following pages. As examples, 

 however, of widely different tastes, I may mention, in ad- 

 dition to the foregoing, that the grey mullets are, like 

 Girella of Australian waters, partly herbivorous; that fiat- 

 fish consume sand-worms and other soft food, the sole feed- 

 ing almost entirely by night ; hake, pollack, mackerel, and 

 others pursue living fishes, chiefly sand-eels and mackerel- 

 midge (young rocklings), at or near the surface. Some 

 fish, as the torpedo, swallow their prey whole, and salmon 

 have been recovered from the interior of the ray without 

 bearing any marks of violence. 



Fish are either oviparous, as the majority of our fishes, 

 spawning at fixed seasons ; or viviparous, as one of 



our blennies, one or more of our sharks, and 

 tion *^® t)ergylt, bringing forth the young alive, 



also at a regular season. Some of the sharks 



and rays deposit the Qgg in a remarkable receptacle known 



as a " purse," those of the sharks being furnished with 



tendrils or filaments, with which they attach themselves 



firmly to weeds or rocks. 



As in the case of birds, much remains to be learnt of 



the periodic concerted movements among the great fish 



families, which, also like the birds, perform 

 Migrations. . i • i • i 



these journeys at a great altitude — in other 



w^ords, near the surface of the water. The general tendency 

 of the present day, on the strength of the careful obser- 

 vations recorded by Cunningham (whose admirable book, 

 recently published, I have had such frequent occasion to 

 quote in the following pages) and others, is to reject many 

 of the more extensive movements, as those of the Arctic 

 lierrings, recorded by the older wTiters with great minute- 

 ness, and to regard the migrations of fishes chiefly as move- 

 ments of more moderate extent to and from deep water 

 for purposes of spawning or in search of food. Even the 

 so-called "stationary" fish, as an examjDle of which we 

 may take the plaice, move about in some degree — one of 



