162 THE HATCHING OF FISH. 



the silvery lamination of the smolt, and refuse to leave 

 the rearing-pond ; while the other half, greater in size, 

 and protected by a different sort of scales, insist on get- 

 ting to the sea, from which, in about forty days, they 

 begin to return as grilses. This anomaly cannot be 

 explained, either by the " little-old-man " similitude of 

 Mr Buckland, or by the difference-in-food theory of Mr 

 Goold and Dr Giinther. It is, we suspect, somehow 

 connected with the recently discovered habit of the 

 salmon species, which occasions a double or divided 

 migration to the sea as smolts, and from the sea in 

 their later stages. When this is better understood, we 

 shall, doubtless, be furnished with new proof of Provi- 

 dential wisdom. 



Mr Buckland, as well beseems a late assistant-sur- 

 geon, treats his readers to a " bit of anatomy." 



" Here," says he, " is a preparation from a salmon, 

 which shows that the ova are thrown off from a long 

 finger-like membrane, one side of which is laminated 

 like the leaves of an opened book ; it is in these leaves 

 that the ova are secreted, and some of them may be 

 seen still adhering in sitti. 



" I have ascertained that behind the ova, ready to 

 be extruded, say this year, are other ova, as small as 

 pins' heads, which will arrive at maturity next year. 

 When the ova are ripe, they detach themselves from 

 the membrane, and lie quite loose in the cavity of the 

 abdomen ; they are not, however, I believe, all shed at 

 the same moment, but at various intervals so say ob- 

 servers of salmon-spawning. They say correctly, as it 

 is not likely that all the ova should become loose at 

 the same moment." 



Attention to this ascertained fact must be paid by 

 all prosecuting pisciculture by means of artificially im- 

 pregnated ova. Excess of pressure endangers the par- 

 turient fish ; and ova prematurely extruded by the 

 manipulator are not in the condition for being im- 

 pregnated by being mixed with the milt. 



