24 THE POPULAR SCIENCE MONTHLY 



him against the ground? In each case, the animal's colors comprise 

 all the background's typical color-notes. Under foliage, the lizard, look- 

 ing 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 dis- 

 covering 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 abori- 

 gines 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 accumu- 

 lation 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 down- 

 ward in all these occupations. And the men of towns look still more 

 predominantly doivn 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 



