DESOR 'S DISCO VER Y. 73 



He had commenced his observations, when suddenly he heard 

 Agassiz calling him, and shouting, " Come, come, make haste ; 

 here are your Mont Rosa fleas." Desor ran to the spot, and 

 saw under a stone the little creatures whom Agassiz persisted 

 in taking to be veritable lice, pretending they had been 

 accidentally brought to these heights. 



" I recognised with extreme joy," says M. Desor, " the little 

 creatures whose loss I had regretted a year before. They are 

 not pretty, but, on the contrary, very ugly. However, they 

 showed, in opposition to the opinion of Agassiz, that they really 

 inhabited the glacier, and were not merely chance visitors. We 

 found them by thousands under other stones. . . . Our guide, 

 with whom the glaciers were old acquaintances, had never 

 seen them before, and the tiny creatures excited his astonish- 

 ment. What surprised us most was the rapidity with which 

 they penetrated into even the most compact ice, till they 

 resembled blood-corpuscles circulating in their vessels. This 

 fact shows that there exist, in the hardest and most transparent 

 ice, certain capillary fissures which escape an unskilled eye : 

 it also proves that the glaciers, on their surface, and down to 

 a certain depth, are by no means incompatible with the de- 

 velopment of organised beings." * 



The tiny insect in question was at first baptized by the 

 name of Desoria saltans (order of the Thysanowa of Latreille), 

 but has since received definitively the name of Desoria glacialis. 

 It belongs to the family of the Podura, singular creatures 



* C. Vogt, Agassiz, und seiner Freunde geologische Alpenreisen, p. 

 181. Frankfort, 1847. 



