Fig. 1. The Egg.
Before the egg is placed within its nidus, this is supplied with the requisite quantity of food needful for the support of the young to the full period of its maturity. The receptacle is then closed, and the same process is repeated again and again until the parent has laid her whole store of eggs. In other cases one tube, or its ramification, contains but one egg. These eggs are usually oblong, slightly curved, and tapering at one extremity; they vary in size according to the species, but are never, however, above a line in length, and sometimes they are very minute. When the stock of the mother bee is exhausted she leaves them to the careful nursing of nature, and the young is speedily evolved. She then wanders forth; time has brought senility; her occupation has gone; and she passes away; but her progeny survive to perpetuate the continual chain of existence.
The Larva.—The temperature of the perforated tube wherein the egg is deposited must necessarily be higher and more equal than that of the external atmosphere, being secluded from its vicissitudes. The egg is soon hatched, and the larva emerges from its shell to feed ravenously upon the sustenance stored up for its supply. This consists of an admixture of pollen and honey formed into a paste, the quantities varying according to the size of the species. By some species it is formed into little balls; by others, it is heaped irregularly at the bottom of the cell. In the case of Andrena the quantity stored is of about the size of a pea. That it must be exceeding nutritious may be inferred from its very nature, consisting, as it does, of the virile, energetic, and fertilizing powder of plants,—the concentration of their living principle. It is strictly analogous to the fecundating property of the semen in animals, and, like them, produces spermatozoa, a fact corroborated by the researches of Robert Brown, Mirbel, and other distinguished vegetable physiologists.[[1]]
[1]. Might not, by parity of inference, the milt of fishes, such as the herring, mackerel, etc., be a useful food in cases of consumption, both from the iodine necessarily existing in it, and also from its doubtless nutritive nature?
We are told that the cells of Hylæus, or Prosopis, and of Ceratina are supplied with a semifluid honey. It is very doubtful if Hylæus collects its own store, but that Ceratina does, I have the authority of an exact observer (Mr. Thwaites) to verify it, for he has caught this insect with pollen on its posterior legs, which the long hair covering the tibia is intended for. What may be the nature of this semifluid honey? It is questionable if the larva could be nurtured upon honey alone without the admixture of pollen, thus contradicting analogies presumable from ample verification in nature’s processes. How, too, does it become semifluid? It is the property of honey, at a certain temperature, to be very fluid, and this is doubtless the temperature that prevails within the receptacle of the larva during the time of the operations of the bees.
Its semifluid consistency could then apparently be produced only by some more solid admixture, which, if not of pollen, of what can it be? This, even in small quantities, might, upon the bursting of its vesicles, have the power of thickening the fluent honey to the necessary consistency.
But a bee without polliniferous organs cannot collect pollen, and the instance of the hive bee, which collects honey in superabundance, feeding its larva with the bee-bread, must inevitably lead to the conclusion that the larvæ of bees require more than honey for their sustenance. Nature is not usually wantonly wasteful of its resources, and if honey sufficed for the nurture of the grub, so much pollen would not be abstracted from its legitimate purpose, nor would bees have this double trouble given to them. By the admixture of pollen the honey has energetic power infused into it by the spermatozoa which that contains. But it must necessarily be collected, for I never observed, nor have I seen recorded, any instance of the pollen being eaten on the flower and regurgitated into the cell in combination with the imbibed honey.
Pollen is eaten by the domestic bee and humble-bee to form wax for the structure of their cells, but the solitary bees do not themselves consume it.
