Sent by Abbott Handerson Thayer, [address not recorded] to Alfred Russel Wallace [address not recorded] on .
No summary available at this time.
An enclosure .
Total Pages : 25
Transcriber: Lord, Annette
Transcription date: August 6, 2014
Scrutiny: 06/08/2014 - Benny, Ruth;
Signed off: no
[Letters S R A H P D O N M E F C J appear in random pattern on back of card
No 3 also shows that even the proximity of a [illeg] contrast of shade, whether on the animal, or near him, tends to obliterate him. The dark patches about the O make it fade when seen far off. Therefore to wear such contrasts is to have them always present as well as always to have a chance of having them better seen than one's own contours.
[Letters S R A H P D O N M E F C J appear in random pattern on back of card]
[Letters S R A H P D O N M E F C J appear in random pattern on back of card (enc 2-1), the letters P, N and E being marked with black dots]
These three photos show the fallacy of the hypothesis that a conspicuous marking makes conspicuous the thing it is on. You will find No. 1 shows the white letters pasted upon a slightly darker ground. Just as the ground color (effectively counter shaded, of course) of most animals, is nearby that of their background, so that, unmarked they would commonly show at least as little against it. In no. 2. I have put dark marks on three of the letters, trying, as Nature does, to make them form figures of their own at the Same time that they make it difficult to see the out line of the white letter they are on. According to the accepted theory these marks should aid the eye in deciphering the letter but they do not. In no[.] 3 I have super added other black marks to complete the obliteration just as Nature does by her abundance of background details repeated in the animal[']s pattern.
Show these three to new comers beginning with the cards on which are the black marks and beginning too far off for them to make out the letters bearing the black marks. All the others will still be legible.
Lay this on some dark surface, to cure the showing through of writing on the back!
This is no.1.
In this photo the highest visible mark on the post is the shadow of the at the bottom of the white card seen in no. 2. The card itself is invisible, on account of coalition with the white sky. These photos show that when seen against the sky, as a deer's white buttocks are commonly seen, by fawns, panthers and wolves on the ground the purest white is the best hope of total invisibility. This causing the sky to be the card's background is simply done by photographing the same card from a lower level.*
A fawn or panther sees a deer's white buttocks from a lower level. This pair of photographs show that the white rumps of deer, antelope, sheep (no.2) and hares are colored in the only way, are of the only color, not to show against the sky, as they bound away from their enemies, especially at night.1
All woodsmen know the need at night, when they hear an animal, of squatting low to try to bring its form against the sky, in order to see it.1
This white, under an open night sky, or by day, in cloudy weather, (because in both these cases the sky illumination is apt to be equally distributed) absolutely reproduces the sky, and effaces the silhouette of the fleeing animal.1
As far as I have been able to investigate species, all animals that could profit by it have even to the jerboa, our only rodent is it not? where height of leap is sufficient to bring him against a sky background for the small carnivora that would eat him. His white tail-tuft must work more or less the same effect. On the other hand all the our slow, scent-hunting, carnivora, skunks, badgers, raccoons, oppossums, the summer wolverine and the black footed ferret, wear more or less white, sky-picturing pattern, on their fronts and tops, and all are nocturnal so that, pattern and all, they are out of sight, by day.1
This photo shows the same white card as the one which is invisible because of coalition with the sky in no 1. This is no.2.
* a fawn cougar or wolf naturally sees this tail f an adult deer's tail from a level lower than that of the tail not to count upon the tail[']s much greater height in the bounding of the scared animal.1
I hope to send you, in a few days, the bird of paradise sketch made wholly out of the bird's three colors, to show how absolutely he, like probably all "conspicuous["] birds, is an actual picture of his background (or in general cases, whatever background they have at the time concealment is worth the most to them[)], just as my blue jay skin picture shows him to be a picture of the leafless season here.1
This Conopatus living where his horizon is commonly treeless [letter deleted] and therefore plain and straight without gaps or points, has a corresponding straight cut-off of white sky-imitation instead of the jagged one of our eastern animal.1
These are of course stuffed specimens.1
In this one you can hardly believe there is a white top to the beast.1
Even when the skunk gets close to his prey his white pattern still passes for sky, and an appearance of a vista between shrubs or more distant trees is the last thing his little victim sees this side the grave (stomach!)1
Doubtless a skunk does get a considerable some portion of his food purely by scent, even to the seizing it, but this service of his white, being beyond dispute, would alone, prove that some element of his habitual prey would escape him, if they saw him while he was waiting to find them by his nose.1
With the sky back ground such as mice and grass hoppers would see him against [it].1
are not these wonderful pictures of shrubs done in skunks' patterns? I mean; do not the skunk's patterns pass, most wonderfully, for shrubs, when seen at a little distance? 1
These were all taken on bright (slightly over cast) days -- at night the deception is infinitely more powerful if a such a thing were possible.1
I feel sure that there is almost or quite no such thing as a conspicuous animal-coloration; that in every case concealment for one purpose or another lead. I mean there is no color made for conspicuousness, of course an elephant, being one who neither preys nor is preyed on has conspicuous monochrome.1
With an abnormal a background to force his white to show.1
1. Written on back of photograph.
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