pollen; and that whatever flowers they first alighted upon decided their choice for that excursion, all other species being passed over unregarded: BUTLER had previously asserted the same thing. Here we see the operation of a discriminating instinct, which in the first place leads the insect to make an aggregation of homogeneous particles, which of course form the closest cohesion; and in the next place prevents the multiplication of hybrid plants. This remark was made by SPRENGEL, who has confirmed the observations of Dobbs, Butler, and others. The bees, which Reaumur observed to visit flowers of different species, might have been in quest of honey as well as of pollen.

CHAPTER XXXVII.

PROPOLIS.

BESIDES the honey and pollen which are gathered by bees, they collect a resinous substance, that is very tenacious, semitransparent, and which gives out a balsamic odour, somewhat resembling that of storax. In the mass, it is of a reddish brown colour; when broken, its colour approaches that of wax. Dissolved in spirit of wine or oil of turpentine, it imparts, as varnish, a golden colour to silver, tin, and other white polished metals. Being supposed to possess medicinal virtue, it was formerly kept in the shop of the apothecary. According to Vauquelin, propolis consists of one part of wax and four of pure resin; in which respect, and in its yielding the same acid, (the benzoic,) it resembles balsam Peru. It also contains some aromatic principles.

With propolis, bees attach the combs to the roof and sides of their dwelling, stop crevices, fasten the hives or boxes to the floors and roofs, strengthen the weak places of their domicile, and varnish the cell-work of their combs. The chapter on Instincts details the modes in which bees employ it for their protection against intruders into their

hives. From its being used for the firm attachment of combs to the roofs of hives, it must be the first matter collected by a recent swarm. The term Propolis is derived from the Greek, and signifies before the city,' bees having been observed to make use of it, in strengthening the outworks of their city.

source.

Reaumur was unable to discover its vegetable It is generally supposed to be gathered from the resinous exudations of the poplar, alder, birch, and willow; according to Riem, from pines and other trees of the fir tribe; though some authors have alleged that bees can produce it where no such trees are near them, and that turpentine and other resins have been disregarded when laid before them. A recent experiment of Huber has solved this question: he planted in spring some branches of the wild poplar, before the leaves were developed, and placed them in pots near his apiary: the bees alighting on them separated the folds of the largest buds with their forceps, extracted the varnish in threads, and loaded with it, first one thigh and then the other; for they convey it like pollen, transferring it by the first pair of legs to the second, by which it is lodged in the hollow of the third. Huber examined the chemical properties of this varnish, and identified it with the propolis which fastens the combs to the hives.

With respect to the absence of fir-trees, &c. in the neighbourhood of the hives, it is to be recollected, in the first place, that bees will fly about three miles (some say five,) for what they may want: HUBER thinks that the radius of the circle they traverse does not exceed half a league, yet says that the question is undecided. In the second place, that a balsamic and tenacious secretion is found upon the buds of several plants and trees, which are often crowded with these insects; such for instance as the tacamahac, horse-chesnut, and hollyhock. Dr. Evans says that he has been an eye-witness of their collecting the balsamic varnish which coats the young blossom buds of the hollyhock, and has seen them rest at least ten minutes on the same bud, moulding the balsam with their fore feet and transferring it to the hinder legs, as above stated. When finally moulded, the pellets of propolis are of a lenticular form.

"With merry hum the Willow's copse they scale,
The fir's dark pyramid, or Poplar pale,
Scoop from the Alder's leaf its oozy flood,
Or strip the Chesnut's resin-coated bud,
Skim the light tear that tips Narcissus' ray,
Or round the Hollyhock's hoar fragrance play.
Soon temper'd to their will through eve's low beam,
And link'd in airy bands the viscous stream,
They waft their nut-brown loads exulting home,
That form a fret-work for the future comb,'
Caulk every chink where rushing winds may roar,
And seal their circling ramparts to the floor." EVANS.

As to the bees refusing resinous substances, when presented to them, as substitutes for propolis, MR. KNIGHT has assured us, in the Philosophical Transactions, that this is not the fact; as he had seen them carry off a composition of wax and turpentine, which had been laid over the decorticated parts of his trees.

The bees blend this substance with wax in different proportions, as occasion may require. Among the ancients, it bore different names, according to the quantity of wax it contained. Virgil made this distinction, though MR. MARTIN Conceives that his narcissi lachrymæ, cera [cum quâ] -" spiramenta tenuia linunt,"-and gluten, all mean the same thing: this is probably a mistake. It seems much more likely that VIRGIL Should mean metys, pissoceron and propolis, the three names by which PLINY says that the varieties of propolis were distinguished in his time.

I have before alluded to the fortification of the weak places of hives with propolis. M. Reaumur, whose hives consisted of wooden frames and panes of glass, wishing to put this talent of the bees to the test, carelessly fastened the glass of a hive with paper and paste, before putting in a swarm; the bees soon discovered the weakness of his paste-work, and indignantly gnawing to pieces this feeble fence, secured the glass with their own

cement.