520 



less considerable than that of the interposed 

 air, did not wet the smooth surface of the slip 

 of whalebone. The transparent air, which pre- 

 cedes a cloud, may sometimes be more humid 

 than the current of air which comes with the 

 cloud. 



It would have been imprudent to remain 

 longer in this thick fog, on the edge of a pre- 

 cipice of seven or eight thousand feet deep *. 

 We descended the eastern dome of the Silla, 

 and gathered in our descent a gram en, that 

 not only forms a new and very remarkable 

 genus, but which to our great astonishment 

 we found again some time after on the summit 

 of the volcano of Pichincha, at four hundred 

 leagues distance from the Silla in the south- 

 ern hemisphere The lichen floridus, so com- 

 mon in the north of Europe, covered the 

 branches of the befaria and the gaultheria odo 

 rata, descending even to the roots of these 

 shrubs. Examining the mosses, which cover 

 the rocks of gneiss in the valley between the 

 two peaks, I was surprised at finding real peb- 



* Toward the north west the slopes appear more accessi- 

 ble. I have" 5 even heard of a path frequented by the smug- 

 glers, which leads to Caravalleda between the two peaks 

 of the Silla. From the eastern peak I took the bearings 

 of the western peak, S. 64° 40' W. ; and of the houses, 

 which I was told belonged to Caravalleda, N. 65°20 / W. 



t Aegopogon ctnchroides. See our Nov. Gen. ct Species* 

 vol. i, p. 132, Tab. xlii. 



