loo THE POPULAR SCIENCE MONTHLY. 



ing some little creature which is content to find its home and its food 

 in the dark ground. Nay, many animals for whom there is no chance 

 of life on the earth, in the water, or in the air, find a refuge in the 

 bodies of other animals and feed on them. 



But in order that all these creatures may live, each in its different 

 way, they must have their own particular tools to work with, and 

 weapons with which to defend themselves. Now, all the tools and 

 weapons of an animal grow upon its body. It works and fights with 

 its teeth, its claws, its tail, its sting, or its feelers ; or it constructs 

 cunning traps by means of material which it sucks out of the water, as 

 in the case of the oyster, or gives out from its own body, like the 

 spider. It hides from its enemies by having a shape or color like the 

 rocks or the leaves, the grass or the water, in which it lives. It pro- 

 vides for its young ones either by getting food for them, or by putting 

 them, even before they come out of the Qgg, into places where their 

 food is ready for them as soon as they are born. 



So that the whole life of an animal depends upon the way in which 

 its body is made ; and it will lead quite a different existence according 

 to the different ' tools with which life provides it, and the instincts 

 which a long education has been teaching to its ancestors for ages past. 

 It will have its own peculiar struggles and difliculties and successes 

 and enjoyments, according to the kind of bodily powers which it pos- 

 sesses, and the study of these helps us to understand its manner of 

 existence. 



And now, since we live in the world with all these numerous com- 

 panions, which lead, many of them, such curious lives, trying, like our- 

 selves, to make the best of their short time here, is it not worth while 

 to learn something about them ? May we not gain some useful hints 

 by watching their contrivances, sympathizing with their difficulties, 

 and studying their history ? And, above all, shall we not have some- 

 thing more to love and to care for when we have made acquaintance 

 with some of life's other children besides ourselves ? 



The one great difficulty, however, in our way, is how to make ac- 

 quaintance with such a vast multitude. Most of us have read anec- 

 dotes about one animal or another, but this does not give us any clew 

 to the history of the whole animal world ; and, without some such 

 clew, the few observations we can make for ourselves are very unsatis- 

 factory. On the other hand, most people will confess that books on 

 2;oology, where accounts are given of the structure of different classes 

 of animals, though very necessary, are rather dull, and do not seem 

 to help us much toward understanding and loving these our fellow 

 creatures. 



What we most want to learn is something of the lives of the differ- 

 ent classes of animals, so that when we see some creature running 

 away from us in the woods, or swimming in a pond, or darting through 

 the air, or creeping on the ground, we may have an idea what its ob- 



