PARAGRAPHS ON PLUMAGE. 25 r 



either by their unstreaked throats, or the impor- 

 tant and marked difference of colour between the 

 sexes characters which embrace the fifty species 

 of which this group is composed. The dozen 

 species of Redstarts are characterised by the 

 colour of their throat (black or dark blue), which 

 is in violent contrast with the colour of the breast, 

 and by the rich chestnut of all but the two central 

 tail feathers of the majority of species. Most of 

 the Chats (of which our Common Wheatear is a 

 typical species) are distinguished from their 

 relations by their white rump, upper tail coverts, 

 and basal portion of the tail feathers. Another 

 very pretty generic pattern of colour is presented 

 in the Jays, numbering a dozen species, in all ol 

 which the wing coverts are barred with black, 

 white, and blue. These patterns of colour are 

 most probably of very remote origin, have been 

 transmitted in a scarcely varying way from the 

 earliest history of the species, and have been 

 preserved while many structural characters of 

 those species have undergone important changes. 

 The manner in which certain patterns of 

 colour are common to distantly related species 

 is also very wonderful and interesting. It is 

 also worthy of remark that these colours are 

 confined to certain parts of the plumage only. 

 What a great variety of birds, for instance, ex- 

 hibit the character of a black cap or hood ! Many 

 of the typical Warblers are so marked, many 

 of the Titmice, many of the smaller Gulls, the 



