378 PIKE AND OTHER COARSE FISH. 



The eggs of the coarse fish hatch out in a very short time, 

 a week or ten days being the average time required. If, then, 

 we had to look to what is called artificial breeding to enable 

 us to increase our coarse fish, the prospect would not be an 

 encouraging one. 



But, fortunately perhaps, artificial breeding is not necessary 

 in the case of coarse fish ; all we need do is to give nature a 

 certain amount of aid, and she will do the rest for us. We 

 must place the parent fish in suitable places for spawning, and 

 then protect the eggs until the fry hatch out. 



It is not only difficult, however, to manipulate the eggs in 

 troughs and trays, but the difficulty of rearing the young fry is 

 even greater still. They are hatched out as perfect fish, almost 

 at once requiring extraneous food, and they are so extremely 

 small that to feed them is a difficult matter. They appear to 

 require that as soon as they leave the egg they should be able 

 to seek their own sustenance on the almost invisible animalculse 

 present in their native waters.' 



The diagram represents what is known in Sweden as Lund's 

 hatching-box. It was invented more than a hundred years ago 

 by a Mr. Lund, of Linkoping. The Swedish inspector kindly 

 furnished me with information about this box, which is in 

 general use in Sweden. He says : — ' Replying to your letter of 

 the 25th of February, 1882, in which you request me to give you 

 some particulars respecting Lund's hatching-box for the propa- 

 gation of summer-spawning fish, I herewith hasten to give you 

 all the information I can. Lund's apparatus is remarkable on 

 account of its being, for aught I know, the first attempt in 

 Europe to promote the propagation of the above-mentioned 



1 The umbilical sac, on the contents of which the trout alevin exists for six 

 weeks, lasts the alevin of the coarse fish but a day or two, and unless the young 

 fish are fed they will die ; hence the difiiculty of rearing them in confinement. 

 Mr. Kelson, of Oxford, last year made the valuable discovery that the animal- 

 culas bred in water containing decayed vegetable matter (like that in which cut 

 flowers have been kept some time) are eagerly devoured by the young fry. I 

 think it is difficult to over-rate the value of this discovery to the breeder of 

 coarse fish. — R. B. M. 



