374 INSECTIVORJE. 



country all the winter. In situation and structure, its nest 

 very much resembles that of the willow warbler; but the 

 eggs are not, perhaps, quite so numerous, and the markings 

 are purple-red, which easily distinguishes them from the rust- 

 coloured markings on those of the others. 



It is very abundant in all parts of the kingdom, being 

 found farther to the north, and also in more bleak and 

 exposed situations, than any of the other warblers, nor does 

 it appear to suffer like the former species from the spring 

 frosts. From the length of time that it not only remains in 

 the country, but continues in song, it probably has two 

 broods in favourable situations ; and that may account for 

 the considerable differences in size and weight that are found 

 in different specimens, and also for the fact of some remaining 

 over the winter. 



In the early part of the winter it feeds upon insects, and is 

 peculiarly serviceable to those bushes and low trees which 

 are subject to have their leaves and young shoots destroyed 

 by aphides : but before it finally leaves the country, the 

 insect supply is greatly diminished ; and as it has been 

 known to eat small seeds in confinement, it probably also 

 does so naturally, in the latter part of the season. 



The difference in habit of the two broods of those migrant 

 and native insectivorous birds that breed twice in the year, is 

 worthy of investigation. The supply of seeds and berries, 

 which is the kind of vegetable food to which insectivorous 

 birds first resort in the autumn, is most abundant at that 

 season, while winged insects are fewer, and there are no 

 larvae, except the birds can dig them out of wood or of the 

 ground, or seek for them in humid places, which would not 

 agree with the structure or the other habits of the sylvan 

 warblers. The second broods must, therefore, be brought up 

 differently from the first, at least they must feed differently 

 when they begin to feed themselves. Now, as difference of 



