12 LIFE AND HER CHILDREN. 
of back-boned animals which will claim a separate 
volume to itself. This division has struggled side 
by side with the other six till it has won a position 
in many respects above them all. Nearly all the 
animals which we know best belong to it, — the fishes, 
toads, and newts (amphibia), the reptiles, the birds, 
and the mammalia, including all our four-footed 
animals, as well as the whales, seals, monkeys, and 
man himself. 
Under these seven divisions then are grouped the 
whole of the living animals as they are spread over 
the earth to fight the battle of life. Though in many 
places the battle is fierce, and each one must fight 
remorselessly for himself and his little ones, yet the 
struggle consists chiefly in all the members of the 
various brigades doing their work in life to the best 
of their power, so that all, while they live, may lead 
a healthy, active existence. 
The little bird is fighting his battle when he 
builds his nest and seeks food for his mate and his 
little ones ; and though in doing this he must kill the 
worm, and may perhaps by and by fall a victim 
himself to the hungry hawk, yet the worm heeds 
nothing of its danger till its life comes to an end, 
and the bird trills his merry song after his break- 
fast and enjoys his life without thinking of perils 
to come. 
" While ravening death of slaughter ne'er grows weary, 
Life multiplies the immortal meal as fast. 
All are devourers, all in turn devoured, 
Yet every unit in the uncounted sum 
Of victims has its share of bliss — its pang, 
And but a pang of dissolution : each 
Is happy till its moment comes, and then 
Its first, last suffering, unforeseen, unfear'd, 
Ends with one struggle pain and life for ever." 
