Note E60 — A RECORD OF THE SUFFERINGS OF THE IMPRISONED COUNTESS LEONORA CHRISTINA. (continued 4)

‘I have in my imprisonment also gained some experience with regard to caterpillars. It amused me at one time to watch their changes. The worms were apparently all of one sort, striped alike, and of similar colour. But butterflies did not come from all. It was quite pretty to see how a part when they were about to change, pressed against something, whatever it might be, and made themselves steady with a thread (like silkworm’s silk) on each side, passing it over the back about fifty times, always at the same place, and often bending the back to see if the threads were strong enough; if not, they passed still more threads round them. When this was done, they rapidly changed their form and became stout, with a snout in front pointed at the end, not unlike the fish called knorr by the Dutch; they have also similar fins on the back, and a similar head. In this form they remain for sixteen days, and then a white butterfly comes out. But of some caterpillars small worms like maggots come out on both sides, whitish, broad at one end and pointed at the other. These surround themselves with a web with great rapidity, each by itself. Then the worm spins over them tolerably thickly, turning them round till they are almost like a round ball. In this it lies till it is quite dried up; it eats nothing, and becomes as tiny as a fly before it dies. Twelve days afterwards small flies come out of the ball, and then the ball looks like a small bee-hive. I have seen a small living worm come out of the neck of the caterpillar (this I consider the rarest), but it did not live long, and ate nothing. The mother died immediately after the little one had come out.’

It is perhaps not unnecessary to add that this observation, which is correct as to facts, refers to the habits of certain larvæ of wasps which live as parasites in caterpillars.