WAX AND COMB CONSTRUCTION, 
189 
Although queen cells (Fig. i, f, g, h) are of a 
different shape and very much thicker, yet the ex- 
cavating instinct is brought to bear upon them too. 
Circular, pits are scooped out, and as Waterhouse 
(167) has shown, where two of these meet they assume 
a straight line between them. 
Wax, when pure, is pale yellow, but sometimes 
nearly white, and the colouring is due, as Dr. Planta 
(130) has pointed out, to pollen consumed by the 
bees. For instance, when bees are collecting pollen 
and honey from heather, the pollen being white, the 
wax is also white ; whereas, when collecting from 
sainfoin, the pollen being orange-coloured, the wax 
also partakes of this colour. 
According to Brande, wax is composed of 80*20 
per cent carbon, 13*14 hydrogen, and 6*36 oxygen, 
but during the process of bleaching it parts with one 
per cent of carbon and absorbs one per cent of oxygen. 
Its specific gravity is between *960 and ‘965, and 
it melts between 145° and 150° Fahr. At 85° it 
becomes plastic, and is then readily moulded and 
kneaded into shape. Bees, besides making wax in 
the way we have described, will use up any wax they 
may find handy, and that from discarded queen cells 
is generally so used. Any impurities contained in 
such wax are incorporated in the walls. 
The coverings of honey cells are usually made of 
wax, but those of brood cells have pollen added to 
make the caps porous ; and for the same reason the 
walls of queen cells have also pollen in them. The 
cappings of drone brood are much more convex 
