ARCHITECTURE. 203 
above is interrupted by suspending rods, or pillars, 
connecting the two combs.. These are placed at 
irregular intervals, but in a regularly graduated size ; 
the mainstay being in the centre, and the slighter 
supports nearer the edge. The lower ends of these 
pillars are attached artistically enough, the base 
spreading like the bole of a tree, with stays running 
out here and there. But the upper end looks very 
ragged and untidy, being, as we have already seen, 
nothing more than the prolongation of the adjoining 
edges of two or three cells, which only gradually take 
the form of round pillars. 
Wasp-paper, the substance of which these delicate 
structures are all made, is composed of various sub- 
stances which are clearly distinguishable under the 
microscope. Each species of wasp has a choice of 
materials, some preferring wood fragments, some 
herbaceous filaments, but nothing seems to come amiss 
when the ordinary supply fails. And grains of sand, 
fragments of bark, paper cuttings, or any other waste, 
are often found among the more usual ingredients of 
wasp-paper. The hornet prefers fragments of rotten 
wood, with which we often find much sand intermixed. 
V. vulgaris makes use of the same materials as the 
hornet, but the particles aresmaller, and better adapted 
to her own capacities. Sometimes, however, she will 
make use of herbaceous filaments, and the style of 
her architecture, like that indeed of all other species, 
differs according to the circumstances in which she is 
placed. 
Thus, to take this instance, in the summer of 1864, I 
had the remains of two nests) of V. vulgaris, which 
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