Cockayne. — Botanical Excursion to Southern Inlands. 251 



straight and stiff, + 3 mm. in diameter, and given off from 

 the more internal and thicker branches at right angles, and 

 sometimes at a lesser angle. The main trunk, according to 

 Hooker, is 10 in. or 12 in. in diameter (46). The leaves are 

 numerous, som6what coriaceous, and their laminae measure 

 about 11mm. x 10mm. The figures in the "Flora Antarc- 

 tica" and "Das Pflanzenreich " (77, fig. 56, p. 334) furnish 

 some idea of the appearance of a small branch of this shrub, 

 but give little notion of the aspect of the plant as a whole. 

 Contrary to the majority of the above-mentioned xerophytic 

 shrubs. S. divaricata usually occurs in the rainy regions of 

 the New Zealand biological area. Such a structure as that 

 described above seems quite unsuited for moist forest regions, 

 and its presence and that of other xerophytic plants can, it 

 seems to me, be only explained on those historical grounds 

 which Dr. L. Diels was che first to suggest. These were 

 that during the great rise of the land, which according to 

 Hutton led to the remarkable extension of the glaciers of 

 New Zealand (53), a steppe or semi-desert climate would 

 exist on the new tableland and plain in the east of New 

 Zealand, and that the plants of that region would require 

 to be modified in accordance with the changed conditions 

 of their existence — from a rain-forest climate to a semi- 

 desert climate — or perish. In accordance with this view, 

 as the land receded to its former sixiall area some of the 

 plants would be left in outlying stations no longer con- 

 nected with New Zealand proper, such as Chatham Islands 

 and the Southern Islands ; others would find a congenial 

 habitat in the extreme xerophytic stations of limited area 

 still remaining in the east and centre of the North and 

 South Islands ; finally, others would get mixed up with the 

 western vegetation at a time of a further sinking of the 

 land, when some of the passes over the Southern Alps 

 would be about 305m. lower than at the present time. But 

 this matter is too important to discuss in the limited 

 space here available ; I can only refer the reader to Diels's 

 original paper (27) and to some further remarks on the 

 subject published by me elsewhere (23). One matter of 

 interest in this connection lies in the fact that Suttonia 

 divaricata shows the rigid divaricating habit of growth 

 in seedlings at quite an early age. Thus, a seedling 6"4 cm. 

 tall has a rigid stem 2 mm. in (iiameter ; near the first leaves 

 one short, straight branch is put forth from the main stem 

 at an angle and in a manner similar to that of the adult ; 

 also, the leaves are equal in size and similar to adult-leaves, 

 except that some of them are more or less toothed or slightly 

 lobed on the margin. So far as I have observed up to the 

 present, it is exceptional for a New Zealand xerophytic shrub 



