SPONGES. 
25 
CHAPTER III. 
Porifera [Sponges). 
What is an animal 1 Nothing seems easier than to 
answer this question. Our thoughts in a moment recall 
the image of the stately horse shaking his neck of thunder, 
and projecting columns of vapour through his translucent 
nostrils ; or the painted tiger crouching in the jungle, 
awaitingin lithe readiness the approach of some unconscious 
antelope to make his mortal spring; or the trembling 
antelope itself, as it pants, and struggles, and groans 
beneath the fangs of its merciless foe. Nothing appears 
simpler than to define an animal. A being with head, and 
body, and limbs ; full of energy and vigour ; possessed of 
various instincts ; master of many ingenious eontri vances 
all helpful to its peculiar economy ; executing various 
movements ; manifesting intelligence in different degrees, 
and governed by a wayward will. 
True, such a creature as this is an animal ; but are 
there no animals but such as possess these characteristics 1 
Let us enumerate a few familiar instances. Look at the 
ferocious crocodile. Is this an animal ? “ Without doubt,” 
you answer. The serpent, the frog, the mackerel 1 
