Before the winter he had only fed at night; now he fed from sunrise to sunset, and at night as well. He fattened steadily, and in proportion, growing more slug-like every day. His horns but emphasized the likeness. He carried them well forward, and, at his rare sleeping intervals, they lay flat against the leaf. Thus with his swollen waist he seemed to fall away both ends. Three times he outgrew his coat. Each time he had eaten till it stretched to bursting point. Each time the process of disrobing was the same.
He dragged his slow bulk to some thick mass of leaves, selected the innermost of them, and spun a web of silk upon its surface. From this he hung himself head downwards. His weight helped him, and, in due course, the old skin split along his back, and he emerged resplendent in a fresh, untarnished, elastic livery.
Each moult was marked by some embellishment. Rusty olive gave place to pale sap green, this in turn to the green of the young willow-leaf, and this again to the green of lush grass. Nor was the change in body colour all. His sides in time were decked with slanting stripes of yellow. A V-shaped orange girdle marked his waist. Its buckle was a tiny splotch of crimson. His horns were tipped with russet brown, and head and tail alike were faintly tinged with blue.
Yet, for all his rainbow tints, Nature had decreed that he should live invisible. To this end she had coloured him to match his food plant. The lines of yellow on his sides broke the monotony of green, as veins break the monotony of a leaf. The blue about him was sister to the blue of summer that played amid the foliage with quivering transparent lights and shadows.
Nor did the cunning harmony end here. In form as well as tint he cheated observation. His outline, as he lay at rest, formed the most perfect outline of a twisted leaf.
(l) growing more slug-like every day. (r) for all his rainbow tints, nature had decreed that he should live invisible.
Birds passed him by unnoticed. Once, and once only, the ichneumon marked him down.
It was after his fifth and final moult. He was just a shade too light for nature, and the ichneumon has a pretty sense of colour. She buzzed viciously through the foliage, and settled for a moment on his back. She had reckoned without her host. His skin was indeed dangerously bright, but it was sensitive in proportion.
Before she could establish herself, a vicious back-sweep of his horns dislodged her.