APRIL 86 



song-thrush is equipped for its peculiar form of nest- 

 building with a development of the salivary glands 

 similar to that of the swift. This provision is carried 

 to extreme in the Chinese swifts, Collocalia, which 

 build the edible nests esteemed by Chinese cooks as 

 stock for soup. This delicacy does not commend itself 

 to European epicures, inasmuch as the nests consist 

 almost entirely of hardened saliva a glutinous secre- 

 tion from the salivary glands of the birds. 



All birds are strictly conservative in the architecture 

 of their nests; so much so, that one need seldom be 

 puzzled to name the species to which an empty home 

 belongs. But there are some differences in detail 

 scrupulously observed by the different species of thrush 

 for which it is not easy to find a reason. The black- 

 bird, the ring ouzel, the mistletoe thrush, the fieldfare 

 and the redwing 1 build on a closely similar general 

 plan, namely, an outer case of dry grass, slender twigs, 

 and sometimes a little moss (the mistletoe thrush is 

 fond of adding wool), heavily plastered with mud or 

 clay inside, and an inner lining of fine grass. The 

 song- thrush starts on a similar plan, but stops short 

 after the plastering process, or, at most, only adds a 

 few fragments of rotten wood. The lining of hardened 

 clay must be as little yielding as a plank bed, which 

 unfeathered bipeds do not relish for repose, yet she 

 provides nothing softer for her long incubation and for 

 the reception of her naked brood when they are 

 hatched. It is singular that none of the thrushes 



1 The fieldfare ( Turdus pilaris) and the redwing (Turdut iliacus) 

 have not been known to breed in Great Britain. 



