We have in this country four different species of the swallow family which visit us every year; they come to us from Africa: these are the sand-martin, two specimens of which we have just seen, the swallow, the house-martin, and the swift. A very little attention will enable you to distinguish these different kinds. The sand-martin is the smallest of the family; as the birds fly by us you notice that the back part is brown, or mouse colour; the under part white. The back of the house-martin is of a glossy black or bluish-black colour; it is white underneath; while the swallow, which is larger than the other two, has a glossy back, like the house-martin; but underneath it is more or less tinged with buff; and see, as I speak here is one flying past us. To-day is the 12th of April, about the time the swallow generally comes to this country. Now you see clearly enough its colour, and you will notice, too, a very marked difference in the form of its tail; see how much forked it is, much more so than the tail of the martin. This forked appearance is produced by the two outer tail feathers, which are much longer than the rest. Now I hope you will take notice of these differences, and call things by their right names, instead of jumbling them all up together under the name of swallow. I have not spoken of the swift, which does not visit this country till May; it is the largest of the swallow family, and has the whole of its body, both above and beneath, of a blackish-brown colour, except a small patch of dirty white under the chin.
"But, papa," said Jack, "do all these four kinds of swallows come from Africa? It is very curious to know how they can find their way backwards and forwards from Africa to this country, and how they come back to the very spots they visited the year before?" Indeed, it is a very curious thing; nevertheless experiments have been made to show that these birds return every year to the same localities.