A CURIOUS TRAIT 201 
that in the animal kingdom there are no Ten Com- 
mandments. Among animals killing is no murder. 
Natural selection, if allowed to work unchecked, pro- 
duces a number of races which think only of themselves 
and their offspring ; a fauna of Ishmaelites, of which the 
hand of every species is upraised against all others. 
This indiscriminate hostility is necessary in the interests 
of the species; it is exercised in self-protection, and 
not from wantonness. There is nothing Nero-like in 
the character of most animals. For the safety of the 
species it is necessary to consider every creature a foe 
until it has proved that it is not. 
As young animals grow up, they are, so to speak, 
educated to distinguish at sight an enemy from a 
harmless species. But if a new creature appear, they 
have no experience to guide them, so rely upon their 
instinct, which teaches them that all unknown organ- 
isms are enemies. They therefore attack it and destroy 
it, if strong enough to do so. By acting in this way 
they are on the safe side. It may be a harmless crea- 
ture, or merely a suffering member of their own species, 
but they do not stay to consider this. Delay may 
mean death, so they either flee from the strange object 
or set upon it and kill it. 
