WHITEFISH OF THE LAKE OF GENEVA 



whitefish with the narrow mouth, I only notice a 

 greyish hash, of which the naked eye cannot make 

 head or tail. But if I take a powerful lens, this hash 

 turns out to be made up of the shells and claws of tiny 

 Crustacea, which have remained after the digestion of 

 the flesh they clothed because of their calcareous 

 nature and their greater hardness. These whitefish, 

 which are as great hunters as the trout but cannot, 

 like them, attack powerful prey because their mouths 

 are too small, content themselves with smaller victims, 

 especially the tiny Crustacea whose remains are found 

 in their stomachs. They snap them up in the water, 

 swallow them by dozens, by hundreds: their quantity 

 makes up for their tiny size, and there are enough of 

 them and to spare. 



The various fishes upon which the flesh-eating 

 trout and char customarily feed also devour these 

 little animals; they feed their own flesh on theirs; 

 and, indirectly, through them, the trout too find 

 themselves dependent upon these minute Crustacea. 

 Consequently, the latter have a supreme importance 

 in the alimentary cycle. Almost the whole responsi- 

 bility for the nourishing of the more powerful creatures 

 which pursue and exploit them rests upon them. The 

 whitefish consume them directly; the trout and char 

 use them through the intermediary of fish which have 

 fed upon them, and we ourselves, at the top of the 

 scale, reach them through both means. Consequently, 

 they must have a truly surprising faculty for reproduc- 

 tion, and a wonderful capacity for adapting themselves, 

 if at the same time they are to maintain themselves 

 and make up for the destruction that goes on all the 

 time. They are the born prey of creatures stronger 

 than themselves, victims chosen in advance for a 

 sacrifice they can never escape, but, none the less, they 

 must survive to some extent in order that the balance 

 may be preserved even if individuals suffer. 



We find in the stomachs of whitefish fragments 



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