]]8 CMMATE AND VEGETATION OF 



is torpid above 14,000 feet, and indeed almost iinifonnly co- 

 vered witli snow. From November till the middle of April, 

 vegetation is also torpid in tiie middle zone (above 10,000 feet), 

 except that a few trees and bushes do not ripen all their seeds 

 till December. The three winter months (December, January, 

 and February) are all but dead in the lower zone (above 6000 

 feet), the earliest appearance of spring at Darjiling (7000 feet) 

 being at the sudden accession of heat in March. From May till 

 August the vegetation in each zone is (in ascending order) a 

 month behind that below it ; 4000 feet being about equal to a 

 month of summer weatlier in one sense. I mean by tliis, that 

 the genera and natural orders Avhich flower at, say 8000 feet in 

 May, are not so forward at 12,000 feet till -Tune, nor at 16,000 

 feet till July. After August, however, the reverse holds good ; 

 then the vegetation is as forward at 16,000 feet as at 8000 feet. 

 By the end of September most of the natural orders and genera 

 have ripened their fruit in the upper zone, though they have 

 flowered as late as July ; whereas October is the fruiting month 

 at 12,000, and November below 10,000 feet. 



The Rhododendrons offer good instances of this : — 



16,000 to 17,000 feet, R. nivale flowers July; fruits September. 

 13,000 to 14,000 feet, E. nnthopogon flowers June; fruits October. 

 11,000 to 12,000 feet, li. campannlahtm flowers in May; fruits in Nov. 

 8,000 to 9,000 feet, R. argenteum flowers in April ; fruits in December. 



And so it is with many species of ComposittE and Umbelliferce, 

 and indeed of all natural orders, some of wliich I have on 

 the same day gathered in ripe fruit at 13,000 to 14,000 feet, 

 and found still in flower at 9000 to 10,000. The brighter 

 skies and more powerful and frequent solar radiation at the 

 greater elevations, account for this apparent inversion of the 

 order of nature. 



I shall conclude this long essay with some notices of the vege- 

 tation of the months in the three zones specified, assuming the 

 elevations of 7000 feet, 11,000 feet, and 15,000 feet, as typical 

 of the three. I shall commence with March, which begins the 

 new year as far as vegetation is concerned at 7000 feet. 



March. — In the lower zone, in which alone vegetation is 

 active, the mean temperature is 50*7°, or 3° below the mean of 

 the year, and 8° to 9° warmer than February. The mean 

 maximum is 58'4°; 68° is the extreme temperature attained in 

 the shade, and 120° in the sun, from my very insufl^icient data 

 for solar radiation in this month. Tlie mean minimum is 43° ; 

 the greatest cold 37°; and when aided by radiation 27'8° ; with 

 a maximum difference of 9° between the minimum tiiermometer 



