92 IXSECT ARCHITECTURE. 



odoriferous, resinous substance, called propolis,^ more tena- 

 cious and extensible than wax, and well adapted for 

 cementing and varnisliing. It was strongly suspected by 

 Reaumur that the bees collected the propolis from those 

 trees which are known to produce a similar gummy resin, 

 such as the poplar, the birch, and the willow ; but he was 

 thrown into doubt by not being able to detect the bees in 

 the act of procuring it, and by observing them to collect it 

 where none of those trees, nor any other of the same 

 description, grew. Plis bees also refused to make use of 

 bitumen, and other resinous substances, with which he 

 supplied them, though Mr. Knight, as we shall afterwards 

 see, was more successful, j 



Long before the time of Eeaumur, however, Mouffet, in 

 his Insectaram Theatrum, quotes Cordus for the opinion that 

 propolis is collected from the buds of trees, such as the 

 poplar and birch ; and Keim says it is collected from the 

 pine and fir.| Huber at length set the question at rest; 

 and his experiments and observations are so interesting, 

 that we shall give them in his own words : — 



" For many years," says he, " I had fruitlessly endea- 

 voured to find them on tre^s producing an analogous sub- 

 stance, though multitudes had been seen returning laden 

 with it. 



" In July, some branches of the wild poplar, which had 

 been cut since spring, with very large buds, full of a 

 reddish, viscous, odoriferous matter, were brought to me, 

 and I planted them' in vessels before hives, in the way of 

 the bees going out to forage, so that they could not be 

 insensible of their presence. Within a quarter of an hour, 

 the}^ were visited by a bee, which separating the sheath of 

 a bud with its teeth, drew out threads of the viscous 

 substance and lodged a pellet of it in one of the baskets of 

 its limbs ; from another bud it collected another pellet for 

 the opposite limb, and departed to the hive. A second bee 



* From two Greek words, irpo ttoXls, meaning before the city, as the 

 substance is principally applied to the projecting parts of the hive. 

 t Phil. Trans, for 1807, p. 242. 

 X Schirach, Hist, des Abeilles, p. 241. 



