TNTRODUCTOHY. 3 1 



and some of them are ascertained to be so — among tlie 

 species whose spawn floats at tlie sni-ftice of tlie se;i, 

 and their ova cannot therefore be Hable to the sh'p^htest 

 injury by any method of fishing wliich is carried on 

 npon or near the ground. For if that be the rule with 

 the spawn of the cod and haddock, there can hardly be 

 a doubt about its being so likewise with the ova of ling, 

 coalfish, whiting, pollack, hake, and torsk (^Brosniius) — 

 all belonging to the same family. Again, turbot, 

 holibut, brill, soles, plaice, dabs, and flounders are all 

 closely allied, agreeing in certain obvious peculiarities of 

 structure and in general habits. It has been ascertained 

 by both M. Sars and M. Malm that the ova of the plaice, 

 one of the most typical of this group of fishes, go 

 through their several stages of development while 

 floating at the surface ; there is every reason to believe 

 therefore that the ova of the other members of the 

 family are subject to the same conditions. Mackerel 

 and gurnards are known to belong also to this cate- 

 gory ; and the dorey, from its affinity to the mackerel, 

 is likely to have the same habit in this respect as that 

 fish. We can say nothing with certainty about bream 

 (Spams), red or grey mullet, or conger. On tlic other 

 hand, we know that tlie herring spawn adheres to the 

 bottom, and that of the pilchard and sprat, it might be 

 anticipated, would be deposited in the same manner; 

 but it has not yet been found there, so fixr as we are 

 aware ; and the late Mr. Jonathan Couch, who probably 

 devoted more time to the study of the habits of the 

 pilchard than any other ichthyologist, states^ that he 

 had reason to suppose that fish spawned at the surface, 

 and the ova became mixed with a large quantity of 

 tenacious mucus wliich spread out like a sheet on the 



^ History of British Fishes, vol. iv., p. 81 (18(15). 



