166 IDLE DAYS IN PATAGONIA 



on account of their simple natural life in the des- 

 ert, which is always green and restful to the eye, 

 or supposed to be so; and because they have no 

 gas nor even candlelight to irritate the visual 

 nerve, and do themselves no injury by poring over 

 miserable books. 



Possibly, then, the beginning of the error was 

 in this preconceived notion, that greenness and the 

 absence of artificial light, with other conditions 

 of a primitive life, keep the sight from deteriorat- 

 ing. The eye's adaptiveness did not get sufficient 

 credit. We know how the muscles may be devel- 

 oped by training, that the blacksmith and prize- 

 fighter have mightier arms than others ; but it was 

 perhaps assumed that the complex structure and 

 extreme delicacy of the eye would make it less 

 adaptive than other and coarser organs. What- 

 ever the origin of the error may have been, it is 

 certain that it has received the approval of scien- 

 tists, and that they never open their lips on the 

 subject except to give it fresh confirmation. Their 

 researches have brought to light a great variety 

 of eye-troubles, which, in many cases, are not 

 troublesome at all, until they are discovered, 

 named with a startling name, and described in 

 terms very alarming to persons of timid character. 

 Frequently they are not maladies, but inherited 

 defects, like bandy legs, prominent teeth, crushed 

 toes, tender skin, and numberless other malforma- 

 tions. That such eye-defects are as common 

 among savages as among ourselves, I do not say, 



