94 THE LIFE OF THE SALMON 



When a female fish spawns she rapidly loses 23 

 per cent, of her weight and a corresponding diminu- 

 tion of body girth. As a kelt the descent to the 

 sea is then made, and thereafter, with a sudden 

 accession of feeding, a marked growth begins, so 

 that the fish may soon be double its kelt weight. 

 If this greatly increased bulk is to be provided 

 with a scale covering, it is clear that one of 

 two things must happen : either new scales must 

 grow amongst the old ones, or the already existing 

 scales must become enlarged — must, in fact, have 

 the power of growth which the body of the fish 

 possesses. 



It has been supposed by some that a shedding of 

 scales takes place at certain periods of the fish's life, 

 and that new scales are formed. It has even been 

 thought by some that the male salmon at the breed- 

 ing season has not a covering of scales. It is true 

 that at this time the male fish is remarkably smooth 

 and slippery, and that the surface is not imbricated 

 in any way by scale edges. This is not, however, 

 from any loss of scales, but because the whole con- 

 dition of the skin has altered and become thickened 

 and toughened. The scales are now deeply em- 

 bedded in their skin pockets, and cannot be got 

 hold of properly unless the thick skin covering is 

 lifted or punctured. But at no time of the fish's 

 life are young growing scales found amongst the 

 existing scales, except in places where repair after 

 injury is going on. There is no arrangement of 

 growing rows of scales ready to take the place of 

 the older scales, as teeth do in the jaws of a Green- 



