Yellow Ones Research Articles

The Perception of Colour

I HAVE not yet heard it stated that our perception of colour is slower for the blue and violet rays than for the green, yellow, and red ones; and as I think that this subject has interest for many of your readers, they will perhaps carry out the following simple experiments on themselves and their friends.

Protective Imitation

I HAVE been watching for hours with great interest what I believe to be a very curious instance of protective imitation. A large old thrush has been, all that time, trying to make itself look like a serpent, and succeeding remarkably well. The object appears to be to frighten away a smaller and more active thrush—no doubt younger and with sharper ears—which seems to be getting all the worms. It appears afraid to attack its young rival, but runs towards it as if it meant to do so, and when the young one turns round and faces it, the old one crouches down so that nothing of it is seen hut a crest-like back, two glaring eyes, the spotted throat, and a dark line formed by the front view of the beak and the lines at the corners of the mouth, which look very much like a serpent's mouth. If I saw the creature protruding from a bush or from the grass, I should certainly take it for a snake of some kind. The young bird looks alarmed and retreats, though just before it was ready to attack the other. No sooner has it recovered its courage and advanced to attack than the old one retreats, and resumes its serpent-like mask. There has been a little sparring in the air occasionally, just enough to show the nature of the feeling, but if allowed to do so the young one evidently would be content to feed quietly. The old thrush (I know it by a small white feather on one wing) is very much at home on this lawn, and seems to consider it as its own private domain, at all events as far as thrushes are concerned. A short time ago, when the ground was for a long time hard from frost and drought, this thrush moped about and seemed nearly starved, and at last fell upon two great clumps of yellow crocuses, and not only tore them to pieces, as if in a rage, but devoured them entirely, returning again and again to them, and gobbling up the yellow petals as a rabbit does a lettuce. At that time many birds that are usually too shy came down from the hills and strolled about the fields and lawns—snipes, plovers, &c. Two exquisite crested plovers (I think they are called) stalked about with graceful dignity for some days in a garden close by, and roosted in an old henhouse. The thrush touched no crocuses but the yellow ones, and no other bird did so. I should be glad to know if the resemblance to a serpent has been observed by any one else.

NOTES ON THE LARVA AND CHRYSALIS OF NEPHELODES VIOLANS

During the last of April and through the month of May, 1877, I found the larvæ of this moth in grassy places in Washington county, Illinois. when full grown they were 1.75 inches long, robust, the head four-sevenths the width of the middle of the body. The color of the under side yellowish gray. Above the line of the lower part of the stigmata, four broad dark brown stripes alternating with three narrow grayish yellow ones, the latter in the dorsal and sub-dorsal regions, and much lighter at the extremities of the body. Head gray, mottled with brown, brown border to the inner part of eyes. cervical shield very dark brown, crossed by dorsal and sub-dorsal light lines. No hairs noticeable except with g1ass.

Yellow Crocuses

INCLOSED is a letter that I had from my friend. Dr. Grierson, Dumfriesshire, a month ago, complaining of a pair of ducks that had gobbled up almost every one of his yellow crocuses, and only the yellow ones. I am further informed by Mr. John Young, Hunterian Museum, Glasgow, that the habit of the sparrows taking the yellow crocuses without touching the blue or striped has been long known to him.