232 



THE REASON WHY 



" Among the dwellings framed by birds 



In field or forest with nice care, 

 Is none that with the little wren's 



In snugness may compare." WORDSWORI 



699. Why is the material composing the exterior of the wrt.tt't 

 nest varied according to the colour of the substance against 

 which the nest is built ? 



Because by this means the nest is 

 rendered undistinguishable from the 

 surrounding objects, and thus best 

 answers the purposes of concealment. 

 If the nest is placed amongst ivy, it is 

 usually constructed of green moss ; but 

 if erected contiguous to some light- 

 coloured branches, it will then be formed 

 of grey lichens. 



700. Beautiful and elaborate is the structure of this tenement, which is generally 

 placed in the middle of a bush, whose whole contracted stems and branches are 

 covered with tufts of many-coloured lichens. To these branches it is not only so 

 assimilated as to seem of natural growth, but is so firmly connected as to render its 

 disengagement impossible, unless by destroying its form and aspect. To obtain if 

 perfect, the branches must be cut away, with the nest undisturbed. Other site*- are 

 occasionally chosen, but in every instance the nest is so artfully hidden as to elude 

 a casual glance. 



The art of concocting nests so as to protect them from depredation appears to 

 be perfectly well understood by some species of birds. No British bird conceals 



its nest more effectually than the water 

 ouzel, a bird common along our trout 

 streams, especially where they wind 

 through rock-girt dales and glens. The 

 nest of this bird may be sometimes dis- 

 covered in the fissure of a low jutting 

 crag, or block of stone, projecting over 

 the rushing and bubbling current, some- 

 times in a crevice on the face of a rock, 

 over which tumbles a cascade, the spray 

 throwing a veil around the spot ; some- 

 times between the rude stones of a 

 ruined bridge, or of a tenantless and dila- 

 pidated water-mill long since deserted. 

 Wherever it is situated, the nest blends undistinguishably with the delicate minute 

 ferns, the moss and lichen, which fill up every chink, peep from every fissure, and 

 give a picturesque t ->ne of mingled tints to the humid face of the grey limestone. 



