Theories and Experiments 301 



d'Orbigny, 140 in speaking of a Peruvian tribe, the Quichuas, who 

 live in the lofty regions of the Cordillera: 



Their bodies are more bulky in the Quichuas than in the other 

 nations of the mountains; we can describe them as characteristic. The 

 Quichuas have very broad and square shoulders, their chests are ex- 

 tremely capacious, very bulging, and longer than usual, which makes 

 the trunk larger; the normal ratio of respective length of the trunk 

 with the extremities does not seem to be the same in the Quichuas 

 as in our European races, and differs equally from that of the other 

 American branches. (Vol. I, p. 226.) 



And the celebrated traveller, struck at the same time by this 

 thoracic amplitude, the habitat of this tribe, and its immunity to 

 the soroche, tries to determine the anatomical fact and to connect 

 it theoretically with the conditions of life of these Indians. 



Let us return to the causes which produce in the Quichuas the 

 great volume we have observed: many researches have made us 

 attribute it to the influence of the lofty regions in which they live 

 and to the modifications resulting from the extreme expansion of the 

 air. The plateaux on which they dwell are always included between 

 the limits of 7500 to 15,000 feet, or from 2500 to 5000 meters above 

 sea level; the air there is so rarified that a greater quantity is re- 

 quired than at sea level for man to find the elements of life in it. 

 Since the lungs need, because of the great volume necessary and their 

 greater expansion during the inspiration, a larger cavity than in the 

 lowlands, from infancy and during the whole period of growth, this 

 cavity receives a great development, quite independent of that of the 

 other parts. 



We wished to ascertain whether, as we should have assumed 

 a priori, the lungs themselves had not undergone considerable modi- 

 fications, as a result of their greater tension. Living in the city of 

 La Paz, which is 3717 meters above sea level, and learning that at 

 the hospital there were always Indians from very populous plateaux 

 of still greater elevation (3900 to 4400 meters), we took advantage of 

 the kindness of our compatriot M. Bernier, physician of this hospital; 

 we asked him to permit us to make the autopsy of the cadavers of 

 some of these Indians of the higher regions, and, as we expected, 

 we found with him that the lungs had extraordinary dimensions, as 

 the outer form of the chest indicated. (M. Burnier showed us, be- 

 sides, that the lungs seemed to be divided into cells much more num- 

 erous than usual. Since this fact seemed to us strange and hard to 

 believe, we asked M. Burnier to repeat these observations on a larger 

 number of subjects; and when, after a few years, we saw this well 

 informed physician again, he confirmed it once more completely.) We 

 noted that the cells are larger than those of the lungs which we had 

 dissected in France; a condition which was necessary to increase the 

 surface in contact with the ambient atmosphere. In summary, we dis- 

 covered: 1. that the cells are more expanded; 2. that their expan- 

 sion increases considerably the volume of the lungs; 3. that conse- 



