THE THRUSH GENUS 383 



underside of the tail, which the bird, when itself in the cup, suddenly 

 bends down from time to time with a spasmodic jerk. This was seen 

 to be done by Mr. E. Selous in the case of a hen blackbird. Another 

 observer, Mr. C. Kingsley Siddal, saw a hen of the same species, 

 while moving slowly round inside the cup with a kind of "kneading" 

 motion, first in one direction, then in the other, frequently pull up 

 the edges of the cup with her bill and press the walls between her 

 lower mandible and her breast. The material for the lining is put 

 into place with the beak, and is then pressed against the inside of 

 the cup with the breast, feet, and probably wings. 1 



Turning from the nest to the eggs, it is worth noting that here 

 again the song-thrush stands apart. Though certain varieties of 

 its eggs resemble those of its congeners, the normal coloration is 

 a clear blue marked with almost black spots ; whereas the normal 

 coloration of the eggs of the blackbird, ring-ouzel, and mistle-thrush, 

 as well as of the fieldfare, redwing, and of several foreign species, is 

 bluish-green, freckled mainly with reds and browns. Some American 

 Thrushes lay clear blue unspotted eggs, as does occasionally the song- 

 thrush, but the combination of blue and black spots appears to be 

 unique within the whole genus unless we except the Oregon-robin 

 (T. ncevius), which is said to lay an egg similarly coloured, in a nest, 

 however, of the ordinary kind, lined with grass. The song-thrush 

 has, in all, three claims to distinction ; its wood plaster, its egg, 

 and lastly, its immense superiority as a songster. Yet in its plumage 

 coloration it is far more typically Thrush-like than, for instance, either 

 the blackbird, the ring-ouzel, or the blackthroated-thrush, a Siberian 

 species, about the size of the fieldfare, which on two or three occasions 

 has been misguided enough to visit the British Isles, and leave its 

 skin in our museums three species which construct the typical nest 

 and lay in it the typical eggs of the genus. If ever it becomes 

 possible to work out the evolution of the genus Turdus, the role of 



1 This account is based chiefly on notes by Mr. Harper Gaythorpe, Mr. C. Kingsley Siddal, 

 and myself, and on information given in Mr. Selous's Bird Life Glimpses, p. 175, and Country 

 Life, February 19, 1910 (A. Taylor). 



