48 BRITISH IND USTRIES. 



that the ova of this fish also float during the whole 

 period of development. This has been proved by both 

 the naturalists I have mentioned ; and there is every 

 reason to believe that turbot, brill, sole, and other 

 closely allied species, do not differ in this respect from 

 their very near relation, the common plaice. Professor 

 Sars has lately succeeded in hatching the eggs of the 

 gar-fish, also found floating ; and as he has been suc- 

 cessful in hatching three or four other kinds of ova, 

 the young fish from which he could not positively 

 identify, and as he is continuing his investigations, we 

 may look forward to further information from him 

 on this interesting and important subject. I have 

 omitted to mention the gurnard among the species 

 whose floating ova he has also identified. It is obvious, 

 therefore, that the idea that fish as a rule deposit their 

 ova on the ground, is a mistaken one ; and the bearing 

 of these discoveries on the possible destruction of fish 

 spawn by the trawl nets, and the consequent injury to 

 our sea-fisheries, need hardly be pointed out. Had I 

 space at my command, I might also bring forward 

 strong evidence to show that the periodical visits of 

 certain fishes to our coasts are not necessarily for 

 spawning purposes, as is generally believed. It is 

 true that large numbers of herrings come near the 

 shore when they are ready to spawn, and that they do 

 spawn there ; but vast numbers of herrings which are 

 not at all in spawning condition also come in. There is 

 no fish which comes nearer the land at certain seasons 

 than the mackerel ; but there is not the slightest 

 doubt about this fish spawning in the open sea; in 



