SCALES, MIRRORS, LEATHERS 



1 ' The improvement is in the ' mirrors ' and ' leathers ' ", 

 my friend answered. "They all reach a couple of 

 pounds, and many of them more. Some, I see, 

 weighed getting on for three pounds. The ' scales ' 

 on the other hand are not so good. Most of them 

 don't amount to more than a pound and a half or a 

 pound and three-quarters. And, as their heads are 

 larger in proportion, and there is more bone in 

 them, their flesh is not so much as that of the others. 

 It's really quite remarkable. I know what I shall do 

 in future. I shall specialize in the ' mirrors ' and 

 1 leathers ', and not bother about the ' scales ' we usually 

 stock in this part of the world. For the time being, 

 at any rate, until I succeed in breeding the best possible 

 type. And I expect to get to work before long." 



My friend was silent for a while as he looked quickly 

 over the pages of his note-book. " It is funny," he 

 said at last, " what a difference there is between these 

 local carp, with their regular dress of scales, and the 

 others, ' mirrors ' or ' leathers ', which have their skin 

 either partially or totally bare. Yet they have all 

 lived side by side in the same pond, have eaten the 

 same food, and shared the same living conditions. 

 Yet, as we see, the others have gained much more 

 than our local fish. That must be a very tempting 

 problem for you, a naturalist." 



" Yes," I said, " it is an interesting problem, and 

 deserves to be investigated. You know, as well as I 

 do, that the ' leather ' and ' mirror ' carp have always 

 been what they are now, or at least from a very early 

 age — in the case of the great majority, at any rate. 

 They do not begin by having normal scales which 

 gradually become modified as they increase in growth. 

 Their peculiar condition is original, appropriate to 

 their particular organization. It arises spontaneously 

 almost everywhere. In the old ponds, both natural 

 and artificial, where the common scaly carp are left to 

 their own devices, we find in greater or fewer numbers, 



99 



