-Mr. R. Spruce on the Musci and Hepatice of the Pyrenees. 99 
even in its most stunted form scarcely passes the upper limit. 
Rhododendron ferrugineum expires in this zone at from 6600 to 
6900 feet, and above this altitude the herbage is composed chiefly 
of Nardus stricta (a grass common in the marshes of the Landes !) 
and of Festuca eskia, Ram. (F. varia y. crassifolia, Koch ; Eskio, 
Jispet and Oursagno of the mountaineers of the Pyrenees). Amongst 
the shrubs characteristic of this zone may be mentioned Vacci- 
nium Myrtillus and uliginosum, Empetrum nigrum, Sorbus cha- 
memespilus and Salix Pyrenaica ; amongst the herbaceous plants, 
Silene ciliata and Arenaria ciliata. Crocus multifidus, which is 
a conspicuous ornament of the lower mountains (as around 
Bagnéres-de-Bigorre), reaches the very summit of the inferalpine 
zone. 
The medialpine zone extends from 7200 to 8400 feet. Festuca 
eskia attains the®upper limit of this zone, but Nardus stricta fails 
below it. Juniperus nana is the giant of the vegetation, already 
so much contracted. Here the weeds which follow the traces of 
man and of the domesticated animals from the plains, cease to 
exist. ‘The following species are abundant in this zone : Statice 
_ alpina, Gentiana alpina, Potentilla nivalis, Cherleria  sedoides, 
Silene acaulis, Iberis spathulata, Berger., and Pyrethrum alpinum. 
Lastly, above 8400 feet, in order to characterise the superalpine 
zone, we have merely to add to the plants of the middle zone 
a very small number of herbaceous plants, all perennial, and 
rarely descending into the medialpine zone. Such are Ranun- 
~ eulus glacialis and parnassifolius, Stellaria cerastoides, Androsace 
alpina, Sibbaldia procumbens, Saxifraga grenlandica, Lap., and 
S. androsacea. 
_ Thus far M. des Moulins. Of the zone below the subalpine, 
which I call the Zona montosa, he says nothing, because it was 
not necessary to his estimation of the flora of the Pic du Midi. 
It corresponds very nearly to Mr. Watson’s ‘Agrarian Re- 
gion,” and were it our sole object to determine the distribution 
of Phanerogamia within its limits, it would be expedient to 
divide it into three zones, as M. des Moulins does the alpine 
region. Ascending from the plain, these zones might con- 
veniently be separated, first by the upper limit of the cultivation 
of the vine, and secondly by that of maize, and the three divi- 
sions would be of nearly equal breadth. The cultivation of the 
vine in the Pyrenees is, as Humboldt observed it to be in South 
America, very nearly coterminous with the natural forests of 
chestnut-trees. It is true that chestnuts occur above the. vine- 
yards, but it is only sporadically ; and so do vines occur here and 
there, trained to cottages in sheltered situations, considerably 
beyond the zone where they normally find a suitable climate. The 
cultivation of maize extends’to about the point where the box 
7* 
