242 THE HISTORY OF CREATION. 



organism which are directly affected by its influence, but 

 other parts also not directly affected by it. This is the 

 consequence of organic solidarity, and especially of the 

 unity of the nutrition existing among all the parts of 

 every organism. If, for example, the hairiness of the leaves 

 increases in a plant by its being transferred to a dry locality, 

 then this change reacts upon the nutrition of other parts, 

 and it ma}^ result in a shortening of the parts of the stalk, 

 and produce a more contracted form of the whole plant. 

 In some races of pigs and dogs — for example, in the 

 Turkish dog — which by adaptation to a warmer climate have 

 more or less lost their hair, the teeth also have degenerated. 

 Whales and Endentata (armadillos), which by their curious 

 skin-coverino: are removed from the other mammals, also 

 show the greatest deviations in the formation of their teeth. 

 Further, those races of domestic animals (oxen and pigs) 

 which have acquired short legs have, as a rule, also a short 

 and compact head. Among other examples, the races of 

 pigeons which have the longest legs are also characterized by 

 the lonofest beaks. The same correlation between the lenofth 

 of the legs and beaks is universal in the order of stilted-birds 

 (Grallatores), in storks, cranes, snipe, etc. The correlations 

 which thus exist between different parts of the organism 

 are most remarkable, but their real cause is unknown to us. 

 In general, we can of course say, the changes of nutrition 

 affecting an individual part must necessarily react on the 

 other parts, because the nutrition of every organism is a 

 connected, centralized activity. But why just this or that 

 part should exhibit this or that particular correlation is in 

 most cases quite unknown to us. We know a great number 

 of such correlations in nutrition ; they are especially seen in 



