128 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
necessitated a remodeling of the skull. On the other hand, the 
skeleton, limbs, hands and feet are but slightly specialized. In the 
elephant tribe, so far as we can trace them back in time, there has 
been little change, save in size, in the structure of the body or limbs, 
while the teeth and skull have passed through a series of remarkable 
changes. It is for this reason that it is unsafe to found a scheme of 
classification, which is meant to be a brief expression of relationship, 
upon a single character, for the result is almost invariably misleading. 
The results of blood tests must be critically examined and checked by 
a comparison with the results obtained by other methods of investiga- 
tion, but after every allowance has been made, these tests are very 
remarkable. 
The blood tests have brought very strong confirmation to the 
theory of evolution and from an entirely unexpected quarter; they 
come as near to giving a definite demonstration of the theory as we 
are likely to find, until experimental zodlogy and botany shall have 
been improved and perfected far beyond their present state. 
