THE object of this work is so fully given in the title-page, that little more remains to be said in the preface.
Beginning with the simplest and most natural form of habitation, namely, a burrow in the ground, the work proceeds in the following order:-2d, those creatures that suspend their homes in the air; 3d, those that are real builders, forming their domiciles of mud, stones, sticks, and similar materials; 4th, those which make their habitations beneath the surface of the water, whether salt or fresh; 5th, those that live socially in communities; 6th, those which are parasitic upon animals or plants; 7th, those which build on branches. The last chapter treats of miscellanea, or those habitations which could not be well classed in either of the preceding groups.
In all these classes a definite order has been preserved, the Mammalia having precedence, and being followed in regular order by the other members of the group. Thus, in the first few chapters, which treat of the Burrowers, the following system has been observed:-First comes Man, the chief of all the mammalia, and in due zoological order follow the Moles and Shrews, the Foxes, the Weasels, the Rodents, and the Edentates. The White Bear alone is removed from its legitimate place, on account of its singular habitation in the snow. The Burrowing Birds come next in order, those which burrow in the earth taking precedence of those which make holes in wood. Burrowing Reptiles follow next in order; and then come the Burrowing Invertebrates, headed by the Crustacea. The same system is followed throughout, so as to give the reader a clear and defi