Sketches from Nature. 317 



riably slow, but if any " accidental sport " occurs 

 which is likely to be of use, it is tenaciously 

 retained, and progress is made at a bound. 



Many of our British birds exhibit capital 

 instances of protective colouring, and it is a 

 somewhat striking fact that birds of sombre 

 plumage build open nests, while the brilliantly 

 coloured birds either have covered nests or build 

 in holes in trees. 



Returning to sexual colour, the dull summer 

 female plumage which characterises so many 

 ground-feeding birds is all the more remarkable 

 as they are the mates of males for the most part 

 distinguished by unusual brilliancy of plumage. 

 The few exceptions to this rule are of the most 

 interesting nature, and go eminently to prove it. 

 In these exceptions it happens that the female 

 birds are more brightly plumaged than the males. 

 But the remarkable trait comes out that in nearly 

 the whole of these cases the male sits upon the 

 eggs. Now this fact more than any other would 

 seem to indicate that the protection afforded by 

 obscure colouring is directly intended to secure 

 the bird's safety during the long and most critical 

 period of its life. This law of protective colour- 

 ing, it will be seen, most influences those species 

 which build on the ground, and one or two 

 examples may be adduced from our own avi- 

 fauna, as in the case of the rare dotterel, which 

 breeds on the fells. In winter the colouring of 



