3 i8 POPULAR SCIENCE MONTHLY. 



esting wasps and hornets of which we have any knowledge. So 

 far as it is known to me, the Vespidce, are all social species, the 

 individuals consisting of males, females, and neuters. They are 

 also known as the "paper-making" wasps, having the habit of 

 constructing paper nests of various sizes and forms in which 

 their young are reared. Our common brown wasps (Polistes) are 

 too well known to require any detailed description. To those 

 living anywhere in the Atlantic States their paper nests are very 

 familiar, being formed of a circular disk of a single tier of cells, 

 being suspended at the solid back by a median pedicle attached 

 to the point chosen by the community to build. Usually these 

 cells face downward, but occasionally the plane of the nest is ver- 

 tical or nearly so, causing the long axes of the cells to lie horizon- 

 tally, or more or less obliquely. This grayish, papery stuff used 

 by the paper-making wasps is a composition of their own manu- 

 facture. In the case of the common wasp it is made by the 

 female ( Vespa vulgaris), she using the fibers of old wood for the 

 purpose. These she gnaws and kneads until they come to be of a 

 consistence of papier-mache pulp the mixture being assisted by 

 the secretion of the salivary glands of the insect. 



The paper hornet ( Vespa maculata) builds often a very large 

 and elaborate nest of this material. These structures are fre- 

 quently found in various localities in the eastern United States 

 and elsewhere. The year before last a colony of them built be- 

 neath the eaves of the tower to my residence in the suburban 

 parts of Washington, D. C. A great paper nest filled the entire 

 angle of the recess. When they build in the forests, however, 

 these insects usually select the smaller limbs of bushes or trees, 

 making the nest more or less spherical or ellipsoidal in contour. 

 Sometimes these are placed high up in the trees, but again may 

 be close to the ground. Two years ago I discovered a deserted 

 one near my present home that was fastened to the twin trunks 

 of a small dogwood, its lower surface being practically in contact 

 with the ground. It was of an egg-shaped form, with the small 

 end downward; the entire affair measuring about thirty centi- 

 metres by twenty-two centimetres, selecting for the purpose the 

 greatest vertical diameter and the longest horizontal one (see Fig. 

 2). Eight distinct layers composed the walls of this nest, and its 

 entrance, a small oval opening, was situated low down in front. 

 It contained three tiers of unipedicled nests of cells, they being 

 closely packed together, and the disks faced downward and were 

 about a centimetre apart. As usual, any single cell was in con- 

 tact with all its juxta-placed neighbors, and when not too closely 

 crowded they were seen to be of a cylindrical form, but if the 

 crowding was closer they then assumed the hexagonal shape. At 

 their bases they were rounded, while inferiorly they were open 



