'PROCREANT CRADLES 107 



nesting-sites. The support of lateral boughs could be 

 largely dispensed with, and the nest firmly clamped to the 

 foundation of one or two large branches, with few or no sup- 

 ports at the sides. Song-thrushes' and missel-thrushes' and 

 blackbirds' nests often grip the branch with a divided clay 

 foundation like the fangs of a double tooth, and the clay will 

 stick to its place till all the twigs and grassy material have 

 vanished with the wear and tear of the seasons, and all that 

 is left is one hard clod. Besides the three birds just named, 

 only the ring-ouzel and the magpie habitually use mud in 

 this particular way. The nests of crows and rooks and 

 ravens are built without it, though after a few months the 

 dead wood and earth on the grass-tufts which they employ 

 decays into a clay-like mass. The use of mud is a convenience 

 rather than a necessity. In the wattle-and-daub cottages 

 built by men clay is used to stop the interstices in the 

 woodwork. But birds do not need it for this purpose, as 

 they keep out wind and rain from the sides by a warm lining 

 of grass or leaves or wool, and rely on their own bodies to 

 keep the eggs and young warm and dry above. 



Weaving is only a finer form of basket-making, and the 

 delicate nests of the finches and warblers differ in detail and 

 not in principle from the solid cradles of the crow and heron. 

 Felting rather than weaving is the human process nearest to 

 that of the smaller birds ; for they do not spin material into 

 strands, and then intertwine it with a regular warp and weft, 

 but twist fibres with their bills and pack them with their 

 breasts into a close mass. Most of them build on a frame- 

 work ; and a lady naturalist has recorded that the first out- 

 line of a golden-crested wren's nest was laid in cobweb. But 

 sometimes a chaffinch's or a long-tailed tit's nest resting on a 

 single bough is built up without other support, and grows 

 like some delicate fungus or chalice of madrepore. The 



