THE PRINCIPLES OF BIOLOGY. 
133 
The nose becomes a formidable weapon only in the 
elephants. 
The eyes can scarcely be reckoned among weapons at all, 
unless it be true that some snakes fascinate and paralyse 
their victims by their glassy and unwinking stare. 
The ears of the horse, donkey, and some other animals 
are defensive only; but they are truly defensive weapons 
against the attacks of the gadfly and the tse-tse. 
The use of a stink-bag, ejecting a pungent and disgusting 
liquid against pursuing enemies, is confined apparently to the 
skunk among mammals, and to two or three beetles among 
insects ; and the ink-bag, rendering the water opaque so as to 
conceal the line of escape, to a few cephalopodous mollusks. 
Nothing perhaps more distinctly marks off the human 
race from all lower animals than the entire absence of 
natural weapons. Man, inhabiting every region of the globe, 
is exposed to the attacks of every carnivorous beast and 
every poisonous insect ; and he captures and eats a greater 
variety of prey than any other creature, yet he is naturally 
unarmed and defenceless. Brain power manifests in him its 
infinite superiority to brute force, and its development con¬ 
tinually widens the gulf between him and his ancient ancestry, 
and opens to him the gateway of a new life. 
THE PRINCIPLES OF BIOLOGY* 
BY HERBERT SPENCER. 
Exposition of Chapters VIII., IX., X., “ The Evolution of 
Life.” 
BY W. H. FRANCE. 
“ How is Organic Evolution Caused ?” 
The title of this chapter is a question which the chapter 
itself does not attempt to answer, except in a negative sense, 
and that only to a very limited extent; but sufficiently so to 
show that to further pursue the subject on such lines would 
be a waste of time and thought. To minds free from bias, 
principles which are erroneous soon show themselves as such, 
and, when recognised, the sooner they are abandoned the 
better. 
* Transactions of the Birmingham Natural History and Micro¬ 
scopical Society. 
