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 may 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-covering 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 longest beaks. The same correlation between the length 
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 
