366 TRAVELS AMONGST THE GREAT ANDES, chap. xix. 



The fact that none of these species were seen at lower eleva- 

 tions cannot be regarded as evidence that they are restricted to the 

 lofty positions at which they were discovered ; though it is unlikely 

 that insects which obviously found themselves ' at home ' under the 

 conditions that were mentioned at pages 113 and 237 will be found 

 at much lower levels, enjoying much higher mean temperatures. 



Upon the whole, it appeared that most individual species had 

 a comparatively small range in altitude in Ecuador. One of the 

 most prominent exceptions to the general rule was the Moth 

 {Erehus odor a, Lin.) which was referred to upon p. 358, that was 

 taken at the level of the sea and nearly ten thousand feet above 

 it. This was exceeded only by one other species, namely, by a 

 AVood-louse which has been identified by the Rev. A. E. Eaton as 

 Metoponorthus pruinosus, Brandt ; and this little Crustacean seems 

 entitled to consideration, for it must possess in a most unusual 

 degree the power of accommodating itself to circumstances.^ 



It now remains to summarize our experiences at low pressures ; 

 and, before recapitulating them, to offer a few general remarks 

 upon the affections, pains and disorders which are so often called 

 Mai de montagne or Mountain-sickness. 



This term has been in use throughout the nineteenth century. 

 It was originally adopted because it was observed that men and 

 other animals were affected in various unpleasant ways upon 

 reaching great elevations on mountains ; and, as it was unknown 

 that the same effects could be produced in mid-air, in balloon, or 

 at the level of the sea by artificial reduction in pressure, it was 

 concluded that they were peculiar to mountains. To the present 

 time, amongst ignorant persons, they are often supposed to arise 

 from purely local causes. 



' It was obtained among roots of trees on the banks of the Guayas, just outside 

 Guayaquil ; in the garden of Seiior Gomez de la Torre at Ibarra (7200 feet) ; at the 

 back of the Hacienda of Guachala (9200 feet) ; on the track between Antisanilla 

 and Pinantura (11,000 feet) ; in the woods on Pichincha (12,000 feet) ; and close to 

 the Hacienda of Antisana (13,300 feet). 



