216 NATURAL HISTORY OF WASPS. 
V. sylvestris, which also presents broad, smooth sheets. 
But the nest of V. britannica is of a thicker structure 
and more compact: the sheets are more numerous, 
closély overlying one another, and the edges are 
pressed down on, and often attached to, the sheet 
beneath them. From the specimens which I have 
seen, I am inclined to believe that the strong con- 
trast of colour of the different stripes, indicating a 
very varied source of supply of materials, is highly 
characteristic of the work of this species. They are 
most determined builders; the remains of a swarm 
will immediately set about to replace the nest of 
which they have been robbed; and the neighbouring 
twigs, under these circumstances, garnished with 
scraps of paper, attest the misdirected energies 
which could not be repressed till the new nest was 
far enough advanced for all the wasps to find space 
to work at, or an end to join on to. 
This species generally builds in low bushes or 
hedgerows, though I have one specimen from the 
top of an apple tree. The outline of the nest is 
pear-shaped, that is to say somewhat drawn out at 
the lower part where the entrance is situated. This 
is single as usual, and lateral, and instead of a simple 
hole there is often a little horn here, a kind of porch 
in which the sentinel, whom it is the habit of this 
species of wasp to post, mounts guard. Dissimilar 
as the mature nest is to that of V. germanica, yet in 
the embryo state the nests of the two species cannot 
be distinguished from each other. It is made of 
vegetable fibres. 
The tree-wasps are less common and have not so 
