prepare and preserve alimentary provision for their families, are
all of a narrowly limited fertility, because the balls of dung, the dead
or paralysed 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
favourite plant, she can ensure 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 half 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 flavour 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