The hair-worm in the first stage of its existence passes its life in the body of some tiny animal or insect. Although it lives afterwards in the water, yet it will, if put into a dry and hot place, dry up to nothing as it were; and then after a long exposure to the heat, if it is put into water again, it will swell out and resume its old proportions, and, live seeming none the worse for being baked.
CHAPTER XXVIII.
Purple Emperor.—His Taste for Carrion.—Wood-pecker.—Blue and Small Copper Butterflies.—Buff-tip Moth.—Moths at Ivy.—Strange-looking Caterpillars.
One hot August day Frank and his faithful follower Jimmy were strolling arm-in-arm along the lanes to call for Dick. Presently they came upon him engaged in no very pleasant occupation. Holding his nose with one hand, with the other he was drawing along a dead dog by means of a long bramble twisted round it. The dog was highly odoriferous, and Frank and Jimmy kept at a distance while they asked him what he was doing that for.
"I saw a purple emperor butterfly flying round the top of one of the oaks in the park. It is impossible to catch it with a net, but I have read that these butterflies have a taste for carrion, and will come down to it; so I just fished about until I found this dead dog, which I mean to lay under the tree as a bait."
"Are you sure it was a purple emperor? They are very rare here," said Frank.
"Oh yes, I saw the purple of its wings shining in the sun, and it was so large, and it flew about the tops of the oaks, and then flew higher still out of sight."
The purple emperor is looked upon as the king of English butterflies. It is a large insect, with wings of dark purple bordered with white, which vary in colour like the material known as shot silk, and in the sunlight gleam most beautifully. The males only have this splendid purple gloss on their wings. The females, though larger in size, have wings of a dull brown. The purple emperor takes its station at the top of the tallest oak and rarely descends to earth. The female is more stay-at-home than the male, and is very rarely caught. The insect would be far oftener seen than caught if it were not for its habit of alighting upon carrion, and collectors take advantage of this low taste, and lie in wait for it, and catch it in the act. The caterpillar is a plump creature, with a tail running to a point, and a pair of horns or tentacles on its head. It is bright green in colour, striped with yellow down each side, and it feeds upon the willow. In the south of England this butterfly is not uncommon, but as you go north it becomes rarer.
Frank and Jimmy accompanied Dick to the park where the oak-trees were, keeping at a respectable distance to windward of him. The carcase was deposited beneath the tree where Dick had seen the purple emperor, and they sat down behind another tree to wait the course of events. Two hours passed away without any sign of the butterfly, but time was no object with the boys, who found it pleasant enough to lie on the cool grass in the shadow of the oaks, and listen to the murmur of woodland sounds. Squirrels and rabbits played about them, and birds fluttered in the trees overhead. The cushat uttered her sleepy moan, and then woke up and flew away on lazy wing to the corn-fields, whence came the sound of the sharpening of scythes. The rattle of the woodpecker tapping the hollow trees was the loudest sound which disturbed the silent, broiling afternoon. The three friends were stretched on the ground talking quietly, and half disposed to doze, every now and then casting glances at the dead dog. Suddenly down a lane of sunlight there fluttered a shimmering purple thing which settled on the carcase, and stayed there, opening and shutting its wings, and sending scintillations of purple light through the green shadows.