Matters are not so arranged in the general balance-sheet of life.  A certain foresight seems to rule over the ovary so that the number of mouths is in proportion to the abundance or scarcity of the food consumed.  The Scarabaeus, the Sphex, the Necrophorus, and other insects which prepare and preserve alimentary provision for their families, are all of a narrowly limited fertility, because the balls of dung, the dead or paralyzed insects, or the buried corpses of animals on which their offspring are nourished are provided only at the cost of laborious efforts.

The ordinary bluebottle, on the contrary, which lays her eggs upon butcher’s meat or carrion, lays them in enormous batches.  Trusting in the inexhaustible riches represented by the corpse, she is prodigal of offspring, and takes no account of numbers.  In other cases the provision is acquired by audacious brigandage, which exposes the newly born offspring to a thousand mortal accidents.  In such cases the mother balances the chances of destruction by an exaggerated flux of eggs.  Such is the case with the Meloides, which, stealing the goods of others under conditions of the greatest peril, are accordingly endowed with a prodigious fertility.

The Bruchus knows neither the fatigues of the laborious, obliged to limit the size of her family, nor the misfortunes of the parasite, obliged to produce an exaggerated number of offspring.  Without painful search, entirely at her ease, merely moving in the sunshine over her favorite plant, she can insure a sufficient provision for each of her offspring; she can do so, yet is foolish enough to over-populate the pod of the pea; a nursery insufficiently provided, in which the great majority will perish of starvation.  This ineptitude is a thing I cannot understand; it clashes too completely with the habitual foresight of the maternal instinct.

I am inclined to believe that the pea is not the original food plant of the Bruchus.  The original plant must rather have been the bean, one seed of which is capable of supporting a dozen or more larvae.  With the larger cotyledon the crying disproportion between the number of eggs and the available provision disappears.

Moreover, it is indubitable that the bean is of earlier date than the pea.  Its exceptional size and its agreeable flavor would certainly have attracted the attention of man from the remotest periods.  The bean is a ready-made mouthful, and would be of the greatest value to the hungry tribe.  Primitive man would at an early date have sown it beside his wattled hut.  Coming from Central Asia by long stages, their wagons drawn by shaggy oxen and rolling on the circular discs cut from the trunks of trees, the early immigrants would have brought to our virgin land, first the bean, then the pea, and finally the cereal, that best of safeguards against famine.  They taught us the care of herds, and the use of bronze, the material of the first metal implement.  Thus