494 INSTINCT OF INSECTS. 



viously to their swarming, in search of a suitable abode a ; 

 and by another, to rush out of the hive after the queen 

 that leads forth the swarm, and follow wherever she 

 bends her course. Having taken possession of their new 

 abode, whether of their own selection or prepared for 

 them by the hand of man, a third instinct teaches them 

 to cleanse it from all impurities 5 ; a fourth to collect 

 propolis, and with it to stop upevery crevice except the 

 entrance ; a fifth to ventilate the hive for preserving the 

 purity of the air ; and a sixth to keep a constant guard 

 at the door c . 



In constructing the houses and streets of their new 

 city, or the cells and combs, there are probably several 

 distinct instincts exercised; but not to leave room for 

 objection, I shall regard them as the result of one only : 

 yet the operations of polishing the interior of the cells, 

 and soldering their angles and orifices with propolis, 

 which are sometimes not undertaken for weeks after the 

 cells are built d ; and the obscure but still more curious 

 one of varnishing them with the yellow tinge observable 

 in old combs ; seem clearly referable to at least two 

 distinct instincts. The varnishing process is so little 

 connected with that of building, that, though it takes 

 place in some combs in three or four days, it does not in 

 others for several months, though both are equally em- 

 ployed for the same uses e . Huber ascertained by accu- 

 rate experiment that this tinge is not owing to the heat 

 of the hives ; to any vapours in the air which they in- 

 clude ; to any emanations from the wax or honey ; nor 

 to the deposition of this last in the cells; but he inclines 



* See above, p. 186. b Huber, ii. 102. c Ibid. i. 18G. ii. 412. 

 a Ibid. ii. 264. VOL. I. 497. e Huber, ii. 274. 



