804 Transactiom.' — Botany. 



plates often projecting from one to two inches beyond the sound portion of 

 the trunk, and exhibiting thin, rounded, weather-worn edges, but perfectly 

 sound, and extremely hard. They vary from -^ to ^ inch in thickness 

 at the base, and may be easily broken off by a sharp blow with a hammer. 

 Unripe trees do not exhibit this peculiarity. 



The remarkable difference in the pubescence of the leaf at different 

 stages of growth has not received the attention it deserves. In the young 

 state the leaves are nearly membranous, and perfectly glabrous. In ex- 

 posed mature specimens the under surface of the leaves is clothed with a 

 layer of closely appressed hairs ; but it is quite a common occurrence to find 

 trees thirty feet high or more with leaves destitute of this hairy covering 

 when growing under the shelter of taller trees. These hairs are unques- 

 tionably adapted to prevent undue evaporation and injury from sudden 

 variations in temperature. Accordingly we only find them developed on 

 leaves fully exposed to the sun and air, whether on young trees or old. 

 They are never developed on seedling plants, or on branches growing under 

 the shade of taller trees. The series of specimens now exhibited will be found 

 very instructive on this head. 



This species appears to attain its northern limit at the East Cape, where 

 it forms a small tree 20 to 30 feet in height. It is plentiful on the lower 

 slopes of the Euahine, Tararua, and Eimutaka Mountains, in the North 

 Island, and widely distributed in the South Island, but does not appear to 

 extend to Foveaux Straits. It descends to the sea-level at Lowry Bay and 

 other places, but appears to be replaced by the mountain beech, which is 

 often mistaken for it. At altitudes above 2,800 feet, with some few ex- 

 ceptions. 



Specimens 100 feet high were observed by Mr. Bidwill at Waiwetu, near 

 Wellington. 



Fagus cliff ortioides, Hook. f. 

 Hook. Ic. PL, t. 673. 

 Mountain Beech. 



Black Birch of portions of Wellington, Canterbury, Otago, and Southland. 



White Birch of Nelson, and in part of Otago and Southland. 



Barely distinguished by the woodman from Entire-leaved Beech. 



The mountain beech bears a close resemblance to the entire-leaved beech 

 in general appearance, although it never attains the extreme dimensions of 

 that species. The leaves are pointed at the apex and rounded or cordate at 

 the base, so that there is but little difficulty in distinguishing the two 

 kinds. 



In the North Island it is confined to the mountain ranges, and appears 

 to attain its northern limit at Lake Waikare on the East Cape. It is most 



