Cockayne. — Plant Geography of the Waimahariri. 131 



actual ridge of the Dividing-range, as far as the upper hmit of 

 the subalpine Fagus formation. This latter formation, how- 

 ever, contains many western plants, especially in its upper 

 portion (e.g., Panax colensoi, P. lineare, &c.), and it forms a 

 distinct natural barrier which shuts off the eastern from the 

 western plants. Its much greater extent and its different 

 constituents separate it from the eastern Fagus formation, and 

 so, although strictly neither eastern nor western in character, it 

 seems more correct to include it in the western plant region. 

 Some western plants also occur at its eastern limit, such 

 as Gunnera dentata, Hymeuopliyllmn armstrongii, and Car- 

 michaelia grandiflora, and this, too, would form a reason for 

 placing it as I have done. The climate of this western region 

 has been indicated already from the meteorological reports of 

 Hokitika and Bealey, but the rainfall must be very much 

 greater than at either of these places ; indeed, I should not be 

 at all surprised to learn that it amounted on an average to 

 200 in. yearly, or even more. The number of rainy days must 

 be very much greater than on the Westland lowland. 



During a stay of six weeks on the summit of Arthur's 

 Pass (900 m.) in the months of December and January, 

 1897-98, I had an opportunity of learning some little about 

 the climate. Durmg that time it rained on more than half 

 the days, the rain sometimes lasting for two days and a half 

 at a time. There was one heavy thunderstorm. My tent, 

 situated on a usually quite dry spot, was not unfrequently 

 filled with water to a depth of 15 cm. The wind blew north- 

 west during the whole of the six weeks, with the exception of 

 a few hours, when a south-west wind gave a slight sprinkle of 

 snow. Once, too, it also snowed from the north-west. The 

 wind blew often with enormous force. Had our tents not 

 been sheltered by trees they would have been frequently 

 levelled to the ground. This excessive wind has written its 

 mark on the vegetation (Plate X.), where the tussocks 

 of Danthonia raoulii are all bent to the south-east. Often 

 when not raining on the pass it was doing so on the ad- 

 jacent heights, and when raining on the pass was fine in 

 the Otira Gorge (W.). During the fine weather it was ex- 

 tremely hot, so much so as to make climbing an exertion. 

 For a few days before our arrival it had been fine, and then 

 the ground and all the vegetation was so dry that one had to 

 be most careful when lighting a fire not to set the forest in a 

 blaze. A creek near the camp was perfectly dry, and so were 

 many watercourses ; yet the rain previous to these few fine 

 days had been excessive for weeks ! Snow lay (December) 

 all over the hills above a height of 1,200 m., and in the river- 

 beds and hollows in the mountains would be quite 15 m. deep 

 in many places. As an example of how deep snow may be 



