Summary and Discussion 321 



We should now apply ourselves particularly to the study of 

 influences of a transitory nature, and by analyzing, in a more 

 detailed manner, the narratives quoted find out whether it is 

 possible to explain these differences by certain conditions of envir- 

 onment, by circumstances in which the travellers are placed by 

 chance, or by this combination of intrinsic conditions peculiar to 

 each of us, some of which may be measured, others more or less 

 unknown and designated by the general expressions of constitution 

 and idiosyncracy. This is the place to investigate the effect of 

 habit and acclimatization and to take into account the race to 

 which the traveller belongs. 



In this last connection, the results observed seem quite contra- 

 dictory: whereas d'Orbigny, Poeppig, Tschudi, de Saint-Cricq, 

 Weddell, the Grandidier brothers, etc., note with astonishment the 

 immunity of the Indians who run beside their mules without 

 showing the least distress, we find, in von Humboldt's ascent of 

 Chimborazo, a half-breed born in the lofty places suffering more 

 than the Europeans; likewise the peons of Caldcleugh, Brand, and 

 Steubel were sick when the travellers themselves felt almost no 

 effects; and yet, in a general way, it is clear that in the Andes the 

 Indians are much more resistant to the effects of mountain sickness 

 than the Europeans are. 



I must quote in this connection a passage from an interesting 

 letter written me by a French engineer, M. E. Roy, former assistant 

 director of the School of Arts and Trades of Lima, who often 

 visited the lofty regions of the Andes: 



The native Indian race is strong and vigorous; nature or the effect 

 of a kind of atavism has endowed it with a powerful respiratory 

 apparatus which permits it, probably by the respiration of a larger 

 quantity of air, to find the oxygen equivalent necessary for its exis- 

 tence and for the maintenance of a good constitution. The Indian of 

 these high plateaux is thick-set, with an enormous torso and pelvis 

 and relatively short legs; he is a walker of the first rank. Shod with 

 his double woolen socks and his moccasins, he will walk 50 kilo- 

 meters, without wincing, in his mountains and provided he has coca 

 leaves to chew, he will make this distance in one stretch. For him 

 and his llamas, a straight line is the shortest distance between two 

 points: he does not try to wind around the valleys to go from one to 

 another, he goes straight ahead, unless the mountain side is impassible; 

 that shows you how necessary it is that he should breathe freely. 



Conversely, when these mountaineers go down to the seashore, 

 they cannot perform any hard work, as they do in their mountains; 

 many contract diseases of the lungs. At the school of which I was 

 assistant director, many of the young men coming from these lofty 

 regions had to return to their native air for this reason before finishing 

 their studies, because the work of the shop was too hard for them. 



