140 HOUSE-MARTEN. 



they do migrate at all, or else that their blood may recover iU 

 true tone and texture after it has been so long benumbed by 

 the severities of winter.* About the middle of May, if the 

 weather be fine, the marten begins to think in earnest of pro- 

 viding a mansion for its family. The crust, or shell, of this 

 nest seems to be formed of such dirt or loam as comes most 

 readily to hand, and is tempered and wrought together with 

 little bits of broken straws, to render it tough arid tenacious. 

 As this bird often builds against a perpendicular wall, without 

 any projecting ledge under it, it requires its utmost efforts to 

 get the first foundation firmly fixed, so that it may safely carry 

 the superstructure. On this occasion the bird not only clings 

 with its claws, but partly supports itself by strongly inclining* 

 its tail against the wall, making that a fulcrum ; and, thus 

 steadied, it works and plasters the materials into the face of 

 the brick or stone. But then, that this work may not, while 

 it is soft and green, pull itself down by its own weight, the 

 provident architect has prudence and forbearance enough not 

 to advance her work too fast ; but, by building only in the 

 morning, and by dedicating the rest of the day to food and 

 amusement, gives it sufficient time to dry and harden. About 

 half an inch seems to be a sufficient layer for a day. Thus, 

 careful workmen, when they build mud-walls, (informed at 

 first, perhaps, by this little bird,) raise but a moderate layer 

 at a time, and then desist ; lest the work should become top- 

 heavy, and so be ruined by its own weight. By this method, 

 in about ten or twelve days, is formed an hemispheric nest, 

 with a small aperture towards the top, strong, compact, and 

 warm ; and perfectly fitted for all the purposes for which it 

 was intended. But then, nothing is more common than for 

 the house-sparrow, as soon as the shell is finished, to seize on 

 it as its own, to eject the owner, and to line it after its own 

 manner.-)- 



After so much labour is bestowed in erecting- a mansion, as 



* We are surprised to find that the more our author seems to have 

 investigated the subject of swallows and their congeners, the greater is his 

 leaning to the side of their hybernation. We need only again refer to our 



to the Greek calendar of Flora, which was kept at Athens by Theo- 

 phrastus, the Ornithian winds blow, and the swallow arrives, between tlie 

 28th February and the 12th March. ~ En. 

 f Soe our note at page 88. EJ>. 



