CORRECTIONS IN THE SHETLAND FLORA. 349 
vertical range of a thousand feet or less! If true, this would be a 
noteworthy fact, inasmuch as the two intermediate zones of the four in- 
clude a vertical range of 1700 or 1800 feet on the mainland of Scot- 
land; so that quite 2000 feet is there required to represent all four, 
the lower and upper very partially. t 
he eultivation of grain being carried on in Shetland, its lower 
levels are within the Super-Agrarian zone, which Mr. Tate limits to 
“an average elevation of 100 feet.” He informs us that the two next 
zones, “the Infer- and Mid-Arctic,” are “not clearly separable, the 
Infer- Arctic extending to at least 600 feet." And he further states 
that the * Super-Arctie zone commences at an elevation of 800 feet 
on Ronas Hill, and its flora is represented by Azalea procumbens, 
Carex rigida, Saussurea alpina, Alchemilla alpina, Salix herbacea, Sib- 
baldia procumbens.” 
It is very evident from these intimations that Mr. Tate has misun- 
derstood the zonal subdivisions of the Arctic or Alpine region in 
Scotland. That which he mistakenly designates the Super-Arctic 
Zone is truly the lower portion of the Mid-Arctic Zone. But, having 
thus jumped at once from the Infer-Arctic to the so-called Super- 
Arctic Zone, he is, of course, unable to find any Mid-Arctie Zone 
between them, and so fancies it somehow lost, or “ not clearly separable 
from " the lower zone. 
There is truly not the slightest indication of the Super-Arctie Zone 
in Shetland, either in the altitude of its hills or by the existence of any 
exclusively Super-Arctic species. Not one of the half-dozen plants 
specially enumerated is peculiar to the highest zone, nor is there any 
one in his printed list which is so. The Alchemilla alpina is found in 
the Super-Agrarian Zone of Scotland; that is, it descends below the 
lowest of the three Arctic zones. The Siddaldia and Saussurea both 
descend into the Infer-Aretie Zone. The three other species all occur 
low in the Mid-Arctic Zone, being more especially the species which 
usually indicate the transition from the Infer-Arctic to the Mid-Arctie 
Zone of plants. Shetland has really three of the six zones only, which 
may be thus indicated :— : 
2. Super-Agrarian Zone, extending from the shores to the upper 
limit of grain-cultivation. A 
4. Infer-Arctic Zone, the space above cultivation, and below the 
appearance of the true Mid-Arctie species, next mentioned. 
