Page:Popular Science Monthly Volume 79.djvu/35

Rh available adaptations of an animal's body will be found ranged against his life-and-death danger.

Out in the open, the zebra's watchful eye and ear, backed by his agility, ensure his safety. But if he pass too near any cover as ample as the lion must have for his operations, his stripes begin to be a safeguard, because cover enough to conceal the lion means reeds or tranches silhouetted across the lion's view of the zebra. The zebra is inevitably against the crouching feline's sky, and his own sky-and-reed counterfeit begins to have the advantage of confusion with the real vegetation through which the lion is condemned to look. A chain is no stronger than its weakest link. What is, obviously, the weakest link in the zebra's life chain? It is when he must risk the lion's ambush and drink. All available powers of getting through this tightest place in his life are sure to be found in operation. This need to drink is as much the crux of the zebra's life as the need to be able to swim would be the crux of a foot-passenger's journey from New York to California, if there were neither boats nor bridges. There will arrive in California no foot-passengers that can not swim, because there is the Mississippi. And there will survive no race of zebras that were not the watchfulest, the agilest and the hardest to see when they had to go through this greatest danger of their lives. It is their Mississippi. When a zebra comes to a drinking-place, the faintest sound that could mean an ambushed lion must not pass undetected by him, and he starts away from the faintest rustle. The crouching lion sees him come into the reeds—sees him all the time—and if the zebra comes within range, springs upon him, but even in his first spring has inevitable difficulty in distinguishing the zebra's outlines because of the absolute similarity of the zebra's imitation of reeds and sky to the real ones. The zebra's uneasiness keeps both the real and the counterfeit in motion together. Very often, doubtless, as the best naturalists seem to agree, the zebra's automatic start comes in time to save him, and the lion's instantaneous now-or-never second spring, such as probably all felines make, must be guided by a lightning-swift perception which of the violently agitated sky- and reed-stripes are the zebra and which are not! Any one who saw my deer at Washington will understand this (and better still will any one who will come to Monadnock and see the wonders of my artificial zebra and oryx). Plainly, then, since the zebra must at this necessary moment be terribly near the lion, his race could not have continued except by having every counter-balancing advantage; and it is demonstrably here that the full magic of his coloration comes into play. These sky-counterfeits are as plainly addressed to the lion's sight, and most of all at the night drinking-place, as the thickness of a grizzly's frontal bone is addressed to the teeth of his enemies.

Colonel Roosevelt has done himself a wrong by not studying our