500 INSTINCT OF INSECTS. — 
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*; a fourth to collect pro- 
polis; and with it to stop up every 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?. i 
In constructing the houses and streets of their new city, 
or the cells and combs, there are probably several di- 
stinct instincts exercised; but not to leave room for ob- 
jection, 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®; 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 di- 
stinct instincts. The varnishing process is so little con- 
nected 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 employed 
for the same uses*. Huber ascertained by accurate ex- 
periment that this tinge is not owing to the heat of the 
hives; to any vapours in the air which they include; to 
any emanations from the wax or honey; nor to the de- 
position of this last in the cells; but he inclines to think 
it is occasioned by a yellow matter which the bees seem 
2 Huber, ii. 102. > Ibid. i. 186. ii. 412. 
© Huber. ii. 264—. Vor. I. 4th Ed. 500. ¢ Huber, ii. 274. 
