demonstrably an increase of such potency of obliterative coloration as belongs 

 to all gorgeously varied costumes, and this at the very period when concealment 

 is most needed. 



It is of great importance to understand that skill and strength are not all 

 confined to predators. It is plain, upon any hypothesis whatever which rec- 

 ognizes the existing fitness of all forms of life to their uses, that this fitness is 

 presumably just as great in the quarry's case as in the hunter's. The fleet- 

 ness and alertness of the hare are a good match for the stealth and power 

 of the lynx, etc., and the consequent balance between predator and prey is 

 doubtless known to the instincts of each animal. The lynx's obliterative col- 

 oration just as much increases his dangerousness to the hare, as that of the 

 hare adds to the lynx's difficulty in catching him. 



Although inconspicuousness is merely an approach to indistinguishability 

 (of course this positive term refers only to occasional effects), yet the practical 

 workings of the two are worth considering . separately. Indistinguishability 

 enables predators to ambush their prey, and, on the other hand, it protects 

 any quarry to the windward of which the predator may pass (if he is not trail- 

 ing it). Mere inconspicuousness of the predator causes him to be less avoided 

 by the animal he preys on, while for the prey it means a minimizing of the 

 stimulus he gives to his enemy's rapacity. Also, at the ultimate moment 

 both sides profit by showing as indistinctly as possible, so that the rapacious 

 animal is harder to dodge, and the prey a fainter target to strike at. Sports- 

 men, insect-catchers, and tennis players will understand this. Again, in a 

 very large class of cases the question is not whether the hawk, for instance, 

 can espy, or the fox, scent, his game, but whether there appear to him, at the 

 moment, sufficient advantages on his side to stimulate him to an effort such 

 as has far more often failed than succeeded. Also, a single instant of success- 

 ful disguise suffices to protect an animal from a swiftly passing marauder, a 

 hawk, for instance. In a rapacious animal's case there must be an eternally 

 shifting balance between greed and inertia. Doubtless a sufficiently strong 

 incentive — a very obvious chance — ^might rouse even the most gorged of 



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