THE SCALES OF THE SALMONID.E 



283 



Spawned fish without discoloration are caught in the 

 nets, as they descend to the sea, up to May. Unspawned, 

 but discoloured and emaciated fish, with ova not fully 

 developed, are caught with the kelts, which are descending 

 in the spring. These fish also exhibit decrepitation marks 

 on their scales. 



Salmon die in very great quantities, and it is doubtful 

 if one salmon in every fifty, which dies after spawning, is 

 recorded or even seen, as they are carried downstream to 

 the sea on the winter and spring floods. 



Injured and unspawned fish with the scale marks and 

 having all the appearance of a stay in fresh water, are 

 captured both in the fixed and drag nets, but it can be 

 assumed that these fish are on their way to effect recovery 

 in the sea. Many persons question the belief that salmon 

 when injured return to the sea. 



Mr. Calderwood, kindly answering some questions by the 

 author, says in a letter, 22nd December, 1913 : 



" A female salmon which has not found a mate, 



even a trout, and has not therefore shed her eggs, 



remains in fresh water for a considerable time." 



And Mr. Calderwood further considers it likely that many of 



the ova will be shed, and that the remainder will be absorbed, 



but, as he says, " this is a supposition." The supposition 



is in this case of course the absorption of the ova. It is 



quite natural to infer that many fish return to the sea as 



spent fish, without having spawned in a natural and 



satisfactory manner. 



Professor Sidney J. Hickson, of Manchester University, can 

 see no reason " why the two oviducts should not pass the separ- 

 ated ova after disintegration as well as in the natural way," 

 that is to say, shed the ova if spawning does not occur. 



Many netters report the capture of half spent and 

 discoloured fish in their nets during April and May, and 



