The oddly-marked caterpillar of the Puss Moth carries the same plan of campaign to a much more artistic pitch. This very quaint insect is common on willows and poplars in England, and is on the whole protectively coloured. Black at first, it looks like a mere speck or spot on the leaf; as it grows, it becomes gradually greener, relieved with broad purple patches on the back, which produce the effect of lines and shadows. When quite full-grown, as seen in No. 7, the adult caterpillar generally rests at ease on the twigs of the willow-tree. Our illustration shows it in this final stage of its larval life, just taking alarm and humping its back at the approach of some bird or other enemy. If the alarm continues, it goes through a most curious series of evolutions, admirably shown by Mr. Enock in No. 8. Here, the little beast is altogether on the defensive: it withdraws its head into the first ring of the body, and inflates the margin, which is bright red in colour. Two black spots, which are not really eyes, but which look absurdly eye-like, now give it a grotesque and terrifying appearance. In fact, the inflated ring resembles a hideous grinning mask, and gives the impression of a face with eyes, nose, and mouth, like that of some uncanny creeping creature. But the apparent face is not a face at all: it is artfully made up of lines and spots on the skin of the body. At the same time that the caterpillar thus assumes its mask, it stands on its eight hind legs as erect as it can, and whips out two pink bristles or tentacles from the forked prongs at the end of its tail--you can see them in the picture. It then bends forward the tail, and brandishes or waves about these pink bristles over its false head, so as to present altogether a most gruesome aspect. Indeed, even Mr. Enock's vigorous sketch of the little brute in its tragic moments does not quite convey the full effect of its acting in the absence of colour: for the bright red margin and the swishing pink switches add not a little to the telling smirk and black goggle-eyes of the mask-like face thus produced _in terrorem_. [Illustration: 7.--CATERPILLAR OF THE PUSS MOTH PREPARING FOR ACTION.]