CHAPTER XIV
THE CABBAGE-CATERPILLAR
The cabbage is the oldest vegetable we possess. We know that people in classic times ate it, but it goes much further back than that, so that indeed we are ignorant of when or how mankind first began cultivating it. The botanists tell us that originally it was a long-stalked, scanty-leaved, ill-smelling wild plant which grew on ocean cliffs. History pays but little attention to such details: it celebrates the battlefields on which we meet our death, it thinks the plowed fields by which we thrive are not important enough to speak of; it can tell us the names of kings’ favorites, it cannot tell us of the beginning of wheat! Perhaps some day it will be written differently.
It is too bad that we do not know more about the cabbage, for it would have some very interesting things to teach us. It is certainly a treasure in itself. Other creatures think so besides man; and one of these is the Caterpillar of the common Large White Butterfly. This Caterpillar feeds on the leaves of the cabbage and all kinds of cabbagey plants, such as the cauliflower, the Brussels sprout, the kohlrabi, and the rutabaga, all near relatives of the cabbage.
It will feed also on other plants which belong to the cabbage family. They are all of the order of the Cruciferæ, so-called by the botanists because the petals are four in number and arranged in a cross. The White Butterfly lays her eggs only on this order of plants. How she knows them is a mystery. I have studied flowers and plants for fifty years and more, yet, if I wished to find out if a plant new to me was or was not one of the Cruciferæ, and there were no flowers or fruit to guide me, I should believe the White Butterfly’s record on the matter sooner than anything I could find in books.
The White Butterfly has two families a year: one in April and May, the other in September. This is just the time that cabbages are ripe in our part of the world. The Butterfly’s calendar agrees with the gardener’s. When there are provisions to be eaten, the Caterpillars are on hand.
The eggs are a bright orange-yellow and are laid in slabs, sometimes on the upper surface, sometimes on the lower surface of the leaves. The Caterpillars come out of their eggs in about a week, and the first thing they do is to eat the egg-shells, or egg-wrappers, before tackling the green leaves. It is the first time I have ever seen the grub make a meal of the sack in which it was born, and I wonder what reason it has. I suspect as follows: the leaves of the cabbage are waxed and slippery. To walk on them without falling off, the grub needs bits of silk, something for its legs to grip. To make this silk, it needs special food; so it eats the egg-wrapper, which is of a horny substance of the same nature as silk, and probably easily changed to the latter in the stomach of the little grub.
Soon the grubs get hungry for green food, and then the ruin of the cabbages commences. What appetites they have! I served up to a herd of these Caterpillars which I had in my laboratory a bunch of leaves picked from among the biggest cabbages: two hours later nothing was left but the thick middle veins. At this rate the cabbage bed will not last long.