POPULAR NATURAL HISTORY FOR BOYS AND GIRLS CEA Pl Resi MAMMALS THERE are over two million species of animals on this earth, and if we were merely to print their names, we should have to mass eight thousand of them on every page of this book. The numbers are, in fact, so appalling and incomprehensible that it is simply beyond human powers to realise the immensity and variety of the mighty Creation amid which we live. The wonderful is not necessarily the unknown ; in> the known we have the wonderful with us. The Creation has a long history, lost in the depths of ages marked by constant change and continuous life. The millions of forms that we know to-day are but as nothing in comparison with those which have vanished for ever in the onward march. Onward unrestingly has come the great army of the living, each form rising to suit its environment, and failing as its environment was modified; Nature