PHYSIOGNOMY OF PLANTS. 



a restless curiosity or unappeasable thirst of knowledge, 

 treads with adventurous but cautious steps : like him 

 strangers in those elevated regions, their presence shows us 

 that the more flexible organization of animal creation can 

 subsist far beyond the limits at which vegetation ceases. 

 The condor, ( 2 ) the giant of the Vulture tribe, often soared 

 over our heads above all the summits of the Andes, at an 

 altitude higher than would be the Peak of Teneriffe if piled 

 on the snow-covered crests of the Pyrenees. The rapacity 

 of this powerful bird attracts him to these regions, whence 

 his far-seeing eye may discern the objects of his pursuit, the 

 soft-wooled Vicunas, which, wandering in herds, frequent,' 

 like the Chamois, the mountain pastures adjacent to the 

 regions of perpetual snow. 



But if the unassisted eye sees life distributed throughout 

 the atmosphere, when armed with the microscope we discover 

 far other marvels. Eotiferse, Brachionse, and a multitude 

 of microscopic animalculse, are carried up by the winds from 

 the surface of evaporating waters. These minute creatures, 

 motionless and apparently dead, are borne to and fro in the 

 air until the falling dews bring them back to the surface of 

 the earth, dissolve the film or envelope which encloses their 

 transparent rotating bodies, ( 3 ) and, probably by means of 

 the oxygen which all waters contain, breathe new irritability 

 into their dormant organs. 



According to Ehrenberg's brilliant discovery, the yellow 

 sand or dust which falls like rain on the Atlantic near the 

 Cape de Verde Islands, and is occasionally carried even to 

 Italy and Middle Europe, consists of a multitude of siliceous 





