You will find—many of you have found already—that the longer you pursue the study of Natural History the more fascinating it seems to become. Now, a part of this fascination is certainly to be traced to the fact that the unsuspected is always happening; and this, too, happens even to those who have studied nature's ways long enough to know that what we call the 'rules of nature' are always subject to exceptions. That is to say, we know that it would be wrong to suppose that, after we have traced out the life-history of any particular creature, we have the key to the life-history of all its near relatives.

For example, you will remember that not long ago we described the complicated history of the starfish, sea-urchins, and sea-cucumbers. Strange and different as were the changes which these creatures passed through when young, we agreed that they were all cast by their parents adrift into the great world while yet so tiny as to require a microscope to see them; and each mother sent forth her young in this defenceless state by the thousand, so that, as a natural consequence, perhaps not more than a dozen of each family survived. But there is one species of sea-urchin which appears to assume some sort of responsibility and tender care for her young ones. This is the Hemiaster sea-urchin. She lays but a few eggs, and these she jealously guards in a number of pouches on her back. Here they hatch, and in due time become young sea-urchins (fig. 2). One of the starfish, again, carries its young on its back under a wonderful tent stretched across the tips of specially constructed spines; and, in order that water may constantly reach her family, the roof of this tent is pierced with holes! Even the unsightly sea-cucumber, or sea-slug, is not to be outdone. In what are known as the 'plated' sea-slugs—so called from the overlapping stony plate borne on the back—the young are housed in a nursery on the back of the mother, the plate referred to serving as a roof (see fig. 1). In another of the sea-slugs the young cling to the skin of the mother until they are big enough to shift for themselves.

In all these cases, you will notice, the extraordinary forms taken by their unprotected relatives during early life are dispensed with. The reason of this is clear after a moment's reflection. The peculiar shapes which we described earlier are so many special devices designed to aid the young in gaining a living until their full-grown shape has been developed. But when these are specially sheltered in nurseries, they have nothing to do but grow, for their food is brought to them.

The higher we search in the scale of animal life, the more numerous and striking become the instances of the love and care shown by parents for their children. Among the fishes and the frogs and toads, for example, there are such wonderful instances of this that we must deal with each of these groups separately.

When we come to birds and mammals, we find it hard indeed to select instances, because, with but few exceptions, these creatures are most exemplary parents. Let us take, by way of example, one or two cases among the mammals.

The ponderous hippopotamus carries her young one on her back when swimming, to save it from the jaws of the hungry crocodile. Some of the opossum family are remarkable for devotion to their young: one species, for example, though considerably smaller than a cat, cheerfully carries her large family about on her back, though each of them is as large as a full-grown rat! They maintain themselves in perfect safety, while the mother climbs about the trees, by twisting their long tails around hers, which is purposely turned forward over her back after the fashion shown in our illustration (fig. 4). Bats, again, undertake what almost seem impossible burdens, for the mother, though she has to obtain all her food when on the wing, refuses to leave her young one, as would seem but natural, in some place of safety, but carries it with her wherever she goes. The little mite clings tightly to the soft fur of the under side of the body (fig. 5). In some cases as many as four baby bats are carried in this way at a time!

The curious Koala, or native 'bear' of Australia, carries her young on her back (fig. 3), and apparently without serious inconvenience, though she has to make her way about the topmost boughs of the giant gum-trees. Finally, we must refer to the kangaroo, which carries its young in a special pouch, too well known to need description here. The point to which we would direct attention is the burden which all these animals are willing to bear for the sake of their young ones.

W. P. Pycraft, F.Z.S., A.L.S.