the family, which in social matters is generally taken as a unit. Numbers of animals living and breeding together may be said to be social by virtue of their contiguity, and, no doubt, are so, to a greater or less extent, in their feelings. But until they help and support one another in some way, true social labour has not begun amongst them. When it does begin it will become distributed through the whole community, and it is only after this early point in social advance has been reached, that the other and greater advance, which consists in the limitation to a certain number of the labour which was before shared by all, can take place.
To this first stage these guillemots have, perhaps, not yet attained, but if some of them are interested in, and show kindness towards, the young of the community generally, as distinct from their own, then, as it appears to me, they are on the way towards it, and when they have reached it they will probably begin to advance socially along the general lines by which both man and social insects have advanced. This is why such a little incident as that I have just recorded is to me a matter of so much interest, so that I get quite excited in trying to be sure about it. It may be little or nothing now, but what does that matter if, in no more, perhaps, than another million of years, it has led to most important developments, if not in guillemots, yet in some other species of bird, possibly in a very great many?—supposing, that is, that we do not exterminate all of them—which is likely,
