138 INSECT ARCHITECTURE. 



of binding and strengthening the walls. These 

 yellow cells also require a much higher temperature 

 of water to melt them than the white ones. 



It appeared evident, therefore, that another sub- 

 stance, diflerent from wax, had been employed in 

 varnishing the orifices and strengthening the in- 

 terior of the cells. M. Huber, by numerous ex- 

 periments, ascertained the resinous threads lining 

 the cells, as well as the resinous substance around 

 their orifice, to be propolis; for he traced them, 

 as we mentioned in our account of propolis, from 

 the poplar buds where they collected it, and saw 

 them apply it to the cells; but the yellow colour is 

 not imparted by propolis, to which it bears no ana- 

 logy. We are, indeed, by no means certain what 

 it is, though it was proved by experiment not to 

 arise from the heat of the hives, nor from emanations 

 of honey, nor from particles of ]>ollen. Perhaps 

 it may he ascribed to the bees rubbing their teeth, 

 feet, and other parts of their body on the surfaces 

 where they seem to rest ; or to their tongue (haustellum) 

 sweeping from right to left like a fine pliant pencil, 

 when it appears to leave some sprinkling of a trans- 

 parent liquid. 



Beside painting and varnishing their cells in tliis 

 manner, they take care to strengthen the weaker parts 

 of their edifice by means of a mortar composed of 

 propolis and wax, and named pissoceros* by the an- 

 cients, who first observed it, though Reaumur was 

 somewhat doubtfid respecting the existence of such 

 a composition. We are indebted to the shrewd ob- 

 servations of Huber for a reconcilement of the Roman 

 and the French naturalists. The details Avhich he 

 has given of his discovery are perhaps the most in- 

 teresting in his delightful book. 



" Soon," he says, " after some new combs had been 



• * From two Greek words, signifying pitch and icax. 



