till seven o'clock in the evening, eighty thousand re-entrances, or four excursions for each bee, supposing there is a population of twenty thousand workers. [82] "L'Intelligence des Bêtes." In 18mo. Paris, 1864. Let us now follow their occupations from the moment in which they establish themselves in a hive. The workers begin by stopping up all the openings except one door, which is always to remain open. A certain number set out to look for a resinous and sweet-scented substance, known under the name of _propolis_, which is destined to cover the inner surface of the hive, as its name shows, which is derived from a Greek word signifying outskirts, or suburb. Huber asserts that it is gathered from the buds of plants. This substance has not yet been employed in the arts, although it possesses the same qualities as wax, as M. de Frarière remarks in his work "On Bees and Bee-keeping."[83] The propolis is employed in Italy for making blisters. This gum is viscous and very adherent. The bee works it up into balls, and carries it in this form to the hive, where other labourers take possession of it. They seize the pellet with their mandibles, and apply it to cracks which they have to make air-tight. They use the propolis for another purpose still, which deserves to be mentioned. [83] "Sur les Abeilles et l'Apiculture." In 18mo. 2e edition. Paris. It happens sometimes that an enemy penetrates into their hive, and that the bees are not strong enough to cast this intruder out of their dwelling. What do they do? As soon as they have discovered the invasion of their domicile, they set upon the impudent intruder, and sting him to death. But how can they drag out the dead body, which is often very heavy? such, for instance, as a slug. On the other hand, it would be dangerous to abandon its carcase in the midst of the hive. A Roman Emperor said that the dead bodies of our enemies always smelt good. This is not the opinion of the bees. They know that if they abandon the carcase in the hive it would infect the place, to the great danger of their health. They therefore embalm it. They encase it in propolis, which preserves it from putrefaction. It is said that the art of embalming was practised for the first time by the ancient Egyptians. It is an error: the first inventors of this art were bees. If, instead of a slug, it is a snail whose evil genius has conducted it into the interior of a beehive, the proceeding is more simple. The moment he has received one sting, the snail retires under the protecting roof of his movable house. The bees thereupon at once wall him in by closing the opening to his shell with this material. The shell is then cemented to the floor of the hive, and the house of the poor mollusc, become its tomb, remains thus in the midst of the hive, as a sort of decorative tumulus. When the sides of the hive are well closed, the bees lay the foundations of their cells.