114 STUDIES IN ANIMAL LIFE. 



sented by the staghound. These staghounds would 

 transmit to their offspring all their specific charac- 

 ters. But, as every one knows, however much dogs 

 may resemble each other, they always present in- 

 dividual differences in size, color, strength, intelli- 

 gence, etc. Now, if any one of these differences 

 should happen to become marked, and to increase 

 by the intermarriage of two dogs similarly distin- 

 guished by the marked peculiarity, this peculiarity 

 would in time become established by hereditary 

 transmission, and would form the starting-point of 

 a new race of dogs say the greyhound unless it 

 were obliterated by intermarriage with dogs of the 

 old type. In the former case, we should have two 

 races of dogs among the descendants of those fig- 

 ured on the Egyptian tombs; but as one of these 

 races would still preserve the original staghound 

 type, Cuvier would refer to it as a proof that spe- 

 cies had not varied. "We, on the other hand, should 

 point to the greyhound as proof that animal forms 

 are variable, and that a new form had arisen from 

 modification of the old. 



An objection will at once be raised to this illus- 

 tration, to the effect that all zoologists admit the 

 possibility of new varieties or races being formed ; 

 but they deny that new species can be formed. It 

 is here that the equivoque of the word species pre- 

 vents a clear understanding of each other's argu- 

 ment. "Whiteness may justly be said to be unalter- 

 able; but white things may vary they may be- 



