200 



OXYLOPHYTES SECT, vi 



dance of lichens and lycopods, the stunted bushes of Coprosma, and the 

 semi-xerophytic ferns certainly point to its classification as a heath ; 

 but, on the other hand, the presence of a grass as the dominant plant 

 seems to mark the society as a meadow . . .' ' The soil of the meadow 

 consists on the surface of rather loose brown peat . . .' ' Amongst the 

 most frequent plants are the following : foliaceous and fruticose lichens, 

 mosses of several species, liverworts . . .' 



These quotations from Cockayne suffice to show that we are dealing 

 with a formation belonging to acid peat soil ; but it deviates so widely 

 from the formations described as occurring in the northern hemisphere 

 that it cannot be grouped with any of these. 



On other islands adjacent to New Zealand the tussock-formation is 

 mainly formed of Poa foliosa, Danthonia bromoides, and Carex trifida. 



In Patagonia, South Georgia, .also on the Falkland Isles and other 

 sub-antarctic islands the tussock-formation occurs. S. Birger x has 

 described the tussock-vegetation of the Falkland Isles. Here it may 

 clothe vast tracts ; the tussocks attain a height and diameter of more than 

 2 metres. The individual tufts are separated from one another by passages 

 of such width that a man can traverse them. The passages are caused by 

 sea-lions, and in the interior of the ' tussock-forest ' one finds abundant 

 animal life. Where the tussocks are close together Poa flabellata domi- 

 nates. The tussock-grass of South Georgia is likewise Poa flabellata ; 

 it attains a height of 1-5 metres ; the large tufts show glaucous leaves, 

 which, though 1-2 metres in length, very consistently withstand the 

 wind ; they are mounted upon thick peaty cushions, which are 50-60 

 centimetres in height and are composed of a mouldering mass of rhizomes, 

 roots, and leaves. In this island the tussock-formation continues from 

 high-tide mark on the shore up to an altitude of approximately 300 metres, 

 and, on the sheltered northern slopes, covers large areas without inter- 

 ruption. The individual cushions are isolated from one another by 

 intervening spaces which are completely hidden by the over-arching 

 leaves of the tussocks. 2 



CHAPTER XLIX. HIGH-MOOR FORMATION 



THE moor, known as high-moor, Sphagnum-moor, sphagnetum, or 

 heather-moor, 3 is mainly formed by bog-moss (Sphagnum) and arises on 

 moist soil, which is only slightly permeable to water, but does not neces- 

 sarily show open water, though very damp air hangs over it. Humid 

 air and dew are essential to sphagnum-moor, which acquires the whole 

 of its moisture from atmospheric precipitations. 4 It often arises on top 

 of old low-moor ; it may also take origin on wet sand, and even on 

 rocks if these be frequently wet, as on the west coast of Norway and 

 Sweden. Bog-mosses prefer abundant atmospheric precipitations, but 

 thrive neither at high temperature nor in dry air. 



The water in high-moor contrasts with that in low-moor by being 



1 S. Birger, 1906. 



2 J. D. Hooker, 1844-7 5 Schenck, 1905 ; Skottsberg, 1906. 

 * See Friih und Schroter, 1904. 



4 See Grabner, 1895 ; Weber, 1894, 1902; Friih und Schroter, loc. cit. 



