THE BRAKE WARBLER. 365 



it comes later in the season; is more local in its distribution, 

 and probably not so numerous, though, from its diminutive 

 size and its retiring habits, it is also less frequently seen in 

 proportion to its numbers. It is about an inch shorter than 

 the white-throat, and proportionably smaller in all its dimen- 

 sions ; but it is only about one-fourth less in weight, so that 

 it is stouter, and not so well adapted for flight. The weights 

 of similar birds should, of course, be as the cubes of their 

 lengths, which, comparing this bird with the white-throat, 

 would give a weight of only about two drachms and a quarter, 

 whereas it weighs rather more than three. The power of 

 flight in birds is not, however, always directly as their lineal 

 dimensions and inversely as their weight, though in birds of 

 similar habits, it approximates to that ratio ; for the power 

 of flight depends on structure, spirit, and many other elements, 

 which are not easily brought within the scope of calculation. 

 The lesser white-throat is, however, a more hideling bird than 

 the white-throat, and more sparing in the use of its wings, 

 both in migration over the country, and in common flight 

 where it does inhabit. There is no well authenticated instance 

 of its being seen in Scotland, or even to the north of the 

 midland heights in England: but still it may be in both 

 places. 



The distribution of its colours is nearly the same as that 

 in the white-throat, only the whole of the under part is purer 

 white, the head and upper part are more ash coloured, and 

 the coverts are relieved with ash colour instead of rusty 

 brown. The bill is wholly dusky, the irides greyish-yellow, 

 and the feet dark smoke grey. The exterior feathers of the 

 tail are white on their outer sides, and light coloured on the 

 inner. 



The bird inhabits the hedges and bushes much more closely 

 than the white-throat, and does not sing on the wing. 

 Indeed it can hardly be said to sing at all, as its note con- 



