222 BRITISH BIRDS. 
The eggs of the Tree-Pipit are from four to six in number, and differ 
so much that it is almost impossible adequately to describe their 
variations. The eggs in each clutch are nearly alike, and it is most 
probable that each bird lays a peculiar type, which it has inherited from 
its parents and transmits to its offspring. The eggs of this bird may be 
classified into two groups—one in which the spots are very small and so 
profusely scattered over the surface as almost entirely to conceal the 
ground-colour, frequently becoming confluent at the large end; the other 
in which the spots are bold blotches and streaks, principally confined to 
the large end of the egg, leaving the rest of the ground-colour distinctly 
visible where the spots are smaller and further apart. Each of these two 
groups may again be subdivided according to colour, one extreme being 
pinkish white and the other pale greenish blue in ground-colour, the spots 
on the former being reddish brown and on the latter sometimes olive- 
brown and sometimes dark reddish brown. Between these extremes 
numerous intermediate varieties occur. The eggs vary in length from ‘9 
to ‘7 inch, and in breadth from ‘65 to 58 inch. What purpose this great 
diversity of colour serves is hard to divine, but it is probably a protective 
one. Dixon has noticed that the darker-coloured eggs are generally found 
in nests in dark situations, as, for instance, under trees or by hedges, 
whilst those of lighter tints are found in the barest situations in the bright 
sunlight, and almost invariably in pasture-fields. The Tree-Pipit may 
sometimes rear two broods in the year; but this is by no means generally 
the case, for after the young are fledged they keep in company with their 
parents for a considerable time. 
The Tree-Pipit is a very wary bird in approaching its nest, and rarely 
betrays its whereabouts. When visiting it the parent bird generally drops 
into the cover some distance from it, and runs through the grass to the 
nest. The female sits very closely, often allowing the mowers to pass 
their scythes over her ere she takes wing. During the whole time the 
female is engaged in incubation the male rarely wanders far from the nest. 
He keeps to his favourite tree, spending his time in song-flights, every 
now and then conveying food to his sittmg mate. He also roosts on the 
ground near his nest; and when the young are able to fly they always 
roost amongst the herbage on the ground. In early autumn the Tree- 
Pipits do not resort to the trees as much as in the earlier part of the year, 
and are never seen to engage in those soaring flights so characteristic of 
the bird in the breeding-season. 
The food of the Tree-Pipit is largely composed of insects, picked up 
from the ground or from the stems of herbage. The bird may often be seen 
on the pastures near grazing cattle, turning over the droppings in search of 
little beetles ; and its young are chiefly fed on caterpillars, small worms, 
and flies. Upon the ground it is very active in its search for food, run- 
