cealment is a series of automatic actions induced 

 through taste, sight, and touch. 



The question yet remains : Whence arises so fal- 

 lible an instinct 4 ? At best, the spider-crab's efforts 

 at self-concealment would seem to result in no 

 decided advantage to the individual or the species. 

 Surely no apparent necessity for camouflage exists 

 in its natural habitat which is in the deeper water 

 — a region of gloom. 



The answer is doubtless to be found in its past. 

 It is more than probable that the ancestors of the 

 spider-crabs — and for that matter all dwellers of 

 the deeper waters and the abysses of the sea — 

 inhabited the sunlit shallows close to the shore. In 

 times past the conditions were not unlikely the 

 same as those prevailing in this area now. The 

 dense population made competition exceedingly 

 keen. Everything edible, living and dead, had 

 scores of ready devourers. In a sense, one half of 

 the population subsisted upon the other half; 

 therefore, the better to avoid serving as food as 

 well as to obtain it for themselves, certain crea- 

 tures learned to simulate their surroundings, some 

 developed swiftness of movement or unusual 

 strength, while still others resorted to actual con- 



[250] 



