REPTILIAN LIVERIES 171 



will become extinct. Where the original striped livery 

 shows a tendency to break up into spots, or bars, irregular 

 marblings, or, by a clustering and blending of groups of 

 spots into large eye-like patterns, or " ocelli," that ten- 

 dency wiU become more and more manifest in this or that 

 particular area if such patterns form a more efficient mark 

 than the original stripes : on the contrary, if they prove 

 less effective, variations in this direction wiU be eliminated. 



The precise degree of importance of this coloration varies 

 indefinitely : it varies with the age of the individual, and 

 with the locality, that is to say with the relative abundance 

 of its enemies if it be a vegetarian, or, on the other hand, 

 with the relative abundance of its prey if it be a predatory 

 animal, for it must not be forgotten that concealing colora- 

 tion is just as important to the hunter as to the hunted. 

 It is never an absolute protection in either case. Move- 

 ment will betray the most cunningly devised mantle of 

 invisibility : scent will effect the same end. ConceaUng 

 coloration only reduces the chance of being eaten, or the 

 chance of death by starvation. 



Finally, the precise coloration of an animal is never 

 caused by its environment. The coloration is the outward 

 and visible sign of the inward invisible physiological pro- 

 cesses going on within the body. All that the environment 

 does is to determine which of an indefinite number of 

 combinations of colour and pattern which make up the 

 potential " coloration " in any given case shall persist. 



As with young mammals and young birds, so with 

 reptiles, where the young are striped the adults are often 

 of one uniform hue, and it is not easy to see why, in the 

 case of the reptiles, the stripes, if they serve any purpose, 

 should cease to be useful in the case of the adult. The 

 coover§e is equally puzzling ; yet there are many cases 



