him against the ground? In each case, the animal's colors comprise all the background's typical color-notes. Under foliage, the lizard, looking up, sees things against a tapestry of dark twigs and the shadow-side of leaves-—the whole mass sharply patterned by bright glimpses through it of the sky above it all. And this ensemble, is precisely what is worn by dusky-coated white-top-striped animals that come between the lizard and this background.
What bewitchment of the student's mind thus holds him from discovering the truth that there is evidently just one universal need of minimized visibility from the point of view which most concerns the creature looked at, and that nature inevitably grants this minimized visibility to all creatures that can use it?
Here is the explanation of the misunderstanding. The basic use of men's brains is one which they share with the lower animals. Like all these animals, man lives, primarily, not by speculative reason, but by what for convenience we may call mere sensation-memory. The aborigines differ from white hunters by their still greater propensity to hunt always where they have once killed.' And a horse that has once been scared by a factory whistle going off too near him on the road always afterward shows alarm when he passes that factory. Man is, we feel sure, one story higher than the other animals, and on top of what he shares with them adds a more or less vigorous layer of "reason." But let anything make the least bit of a run on this reason-bank, and he is bankrupt indeed, and falls back on his sensation-memory.
Let us examine a few of the limitations governing the vast accumulation of man's sense records. Here, for instance, is a thing seldom thought of: Man is, mainly, a looker-down—perhaps as much so as a cow. He tills the soil, he hunts, he fishes—largely or wholly looking downward in all these occupations. And the men of towns look still more predominantly down on desks, tables, tool-benches, etc. This habitual down-looking of men is well attested just now in New England by the difficulty the hunters for the brown-tail moth nests have in accustoming their eyes to day-long searching of the tree-tops. A few weeks of this looking up strains their eyes. Another proof of all this is that men say white is the color that shows by night. This is the idea of a race that mainly looks downward. A mouse, on the contrary, because almost everything comes between him and the sky, would consider black the color that showed best in the night. Now when some one asks us to form a clear idea of the mouse's (and the creeping lion's and leopard's) view of the animal kingdom, our thinking-power balks, and we fall back on our sensation-memory, which vouchsafes us, generally, not a single instance of view from this low level, while it deluges us with memories of the bird's-eye view that we habitually get of these same species. If we are forced for a moment into the realm of thought, in the next