_Mrs. B_. The peculiar formation of the foot plainly discriminates them, for it is so disposed, as to carry all its four toes forward; which clearly accounts for the difficulty it finds in walking. As they arrive later, so they retire sooner than the others, being seldom seen after the middle of August. Are you not tired, my children, with my long account of these birds? "Oh no, dear mamma: pray tell us something about sand-martins too," exclaimed each of the children; "we shall then be able to distinguish each of the four species of British _hirundines_." Mrs. Bernard assured them, she would willingly comply with their request, as far as she was able to do it: "but," added she, "it is difficult to gain full and exact information respecting the lives and habits of these little birds, which are extremely wild by nature, disclaiming all domestic attachments, and haunting heaths and commons, far from the resorts of man. They are very fond of water, and are never known to abound but near vast pools or rivers. They form their nests in a manner totally different from the varieties I have mentioned; boring a round hole in the sand, in a serpenting direction, and about two feet deep. At the further end of this burrow, they form their rude nest; consisting of fine grass and feathers, laid together with very little art. It is wonderful to observe what arduous undertakings perseverance will accomplish. One would suppose it almost impossible that this feeble bird, with its soft bill and tender claws, should be able to bore a stubborn sand-bank, without injury. Sand-martins are much smaller than any other species of _hirundines_, and also differ from them in colour, being what is termed mouse-colour, instead of black. They fly also in a peculiar manner, by jerks, somewhat resembling a butterfly. They are by no means so common as the other species; for there are few towns or large villages that do not abound with house-martins; few churches, towers, or steeples, but what are haunted by swifts; scarcely a cottage chimney that has not its swallow; whilst the bank-martins, scattered here and there, live a sequestered life, in sand-hills and in the banks of rivers." _Ferdinand_. Do they sing, mamma? _Mrs. B._ No, my dear; they are particularly mute, only making a little harsh noise when any person approaches their nest. They lay from four to six white eggs, and breed twice in the season. _Louisa_. Have you any thing more to tell us on this amusing subject, my dear mother? _Mrs. B._ No, my dear: I believe I have now told you most of the important particulars respecting these curious little birds. But I have an account in my pocket-book, which I extracted from a book I was reading last week--"Bingley's Animal Biography:" I will read that to you, if you please. It is respecting a foreign species of _hirundines_, called the esculent martin.