ANNUAL INCREASE OF THE HEEEING. 5 



conducted with attention to details, and -without any desire 

 to exaggerate : these give the following results : — Cod-fish, 

 3,400,000; flounder, 1,250,000; sole, 1,000,000; mackerel, 

 500,000 ; herring, 35,000, and smelt, 36,000. 



Any person who wishes to manipulate these figures may try 

 by way of experiment a few calculations with herring. The 

 produce of a single herring is, say, thirty-six thousand eggs, but 

 we may — the deduction being a most reasonable one^ — allow that 

 half of these never come to life, which reduces the quantity to 

 eighteen thousand. Allowing that the young fish are able to 

 repeat the story of their birth in three years, we may safely 

 calculate that the breeding stock by various accidents will be 

 reduced to nine thousand individuals ; and granting half of these 

 to be females, or let us say, for the sake of rounding the figures, 

 that four thousand of them yield roe, we shall find by multiply- 

 ing that quantity by thirty-six thousand (the number of eggs in 

 a female herring) that we obtain one hundred and forty-four 

 millions as the produce in three years of a single pair of herrings ; 

 and although half of these might be taken for food as soon as 

 they were large enough, there would still be left an immense 

 breeding stock even after aU casualties had been given efieot to ; 

 so that the devastations committed on the shoals while capturing 

 for. food uses must be enormous, if, as is asserted, they affect 

 the reproductiveness of these useful animals. Of course this is 

 but guesswork. Practical people do not think that, taking all 

 times and seasons into account, five per cent of the roe of our 

 herrings come to life. 



It is known even to tyros in the study of natural history, 

 as well as anglers and others interested, that the impregnation 

 of fish-eggs is a purely external act ; but at one time this 

 was not believed, and a portion of the experiments at the Stor- 

 montfield salmon-breeding ponds was dedicated to a solution of 

 this question, with what result may be guessed. The old theory, 

 that it is contrary both to fact and reason that fish can differ 

 from land animals in the matter of the fructification of their 

 eggs, was signally defeated, and the question conclusively settled 

 at the ponds in a very simple way — namely, by placing in the 

 breeding-boxes a quantity of salmon eggs which not having been 

 brought into contact with milt, rotted away. Curious ideas used 

 to prevail on this branch of natural history. Herodotus observes 

 ' of the fish of the Nile, that at the spawning season they move 

 in vast multitudes towards the sea ; the males lead the way, 



