THE MOUNTAIN. 135 



astronomer, no such simultaneous shedding of 

 leaves takes place. The tree is constantly part- 

 ing with a portion of its leaves, and as constantly 

 repairing its loss, so that no phenomenon takes 

 place similar to that which we call the fall of the 

 leaf. Quite analogous to this is the moulting of 

 birds, which are constantly casting off their old 

 plumage and assuming new; so that, like ever- 

 greens, and the palms of the tropics, they always 

 present nearly the same appearance. 



I cannot pursue this subject farther at present, 

 interesting though it is, but will remark merely, 

 that in climates which are subject to very long 

 droughts, during which no plants can derive any 

 nourishment from the ground, the roots of such 

 as are not supported by the air only choose this as 

 their season for resting. They shut up all their 

 pores, so as to lose none of their stock of moisture 

 by evaporation, and remain, perhaps for a very 

 long time, buried in the driest sand, or imbedded 

 in a hardened mass of the closest clay, but, on the 

 return of the rainy season, spring suddenly into 

 life and verdure. But it is time for me to return 

 to my subject. 



Just below the summit of the mountain, we 

 came upon a small lake or tarne, round the shores 

 of which we found a variety of mosses, but very 

 few flowering plants none indeed which could 

 be considered rare. The season for Alpine plants 

 had scarcely yet arrived ; for my companion, who 

 visited the same spot about two months after- 

 wards, found growing in the greatest abundance 

 many plants of which we now saw no signs. 



The last part of our ascent was performed very 

 quickly, for the recollection of the prospect which 



