Thomson. — Bofaitical Evidence ag(tiii><t Recent Glaciation of X.Z. 351 



O. operina, 0. angustifolia, 0. Traillii, 0. Colensoi, and 0. Lyallii ; Olearia 

 jragrantissima, with its heads collected into aggregate or compound heads : 

 no less than thirty-four species of Celmisia, showing a great degree of 

 modification ; the remarkable Raoulias of the " vegetable sheep " type 

 {R. eximia and R. mammillaris) ; Rnoidia gmndiflora, a type differing from 

 all the others of the genus ; several highly differentiated species of Senecio, 

 including the climbing S. scindopkUus, and *S. geminatus, a form allied to 

 certain genera found in Juan Fernandez, and so distinct that Hooker 

 formerly placed it in a distinct genus, Traversia ; PhijUachne clavigera, a 

 most singular plant, allied to a Fuegian form ; Lobelia Roughii, " a most 

 distinct species, quite unlike any other " of the genus in its three-lipped 

 corolla ; Mitrasacme novce-zealandice and M. montana, the latter either iden- 

 tical with or very nearly allied to a Tasmanian species, while the other 

 species are mostly Australian or south Asiatic. Then we have the re- 

 markable development of the genus Veronica, in which occur some curious 

 groups of forms: (1) the "whip-cord" species — V. GiUesiana, V. tetra- 

 sticha, V. quadrifaria, V. tuniida, V. h/copodioides, V. Hectori, V. coarctata, 

 V. salicornioides, V. Armstrongii, V . propinqua, and V . cupressoides ; (2) the 

 three moss-like species — V. pulvinaris, V. Thomsoni, and V. ciliolata, ori- 

 ginally separated by Hooker as a separate genus Pygmaea ; (3) the 

 anomalous V. loganioides. a species quite distinct from any other of the 

 genus, and whose relationships are somewhat obscure ; and (4) the curious 

 dried-up-looking forms V. Cheesemanii and V. canescens. Altogether, the 

 Veronicas constitute a group of forms which have probably been long 

 isolated to bring about the remarkable differentiation which they now 

 exhibit. 



I have gone minutely into these details, and drawn my facts from an 

 analysis of Mr. Cheeseman's Manual, because it is important in such a 

 connection to show as fully as possible the evidence on which I base my 

 opposition to the idea of a recent glacial epoch in New Zealand. 



II. 



One of the effects of the recent glaciation of the Northern Hemisphere 

 was to produce among the woody plants which followed the ice in its retreat 

 northwards a deciduous-leaved character. Woody plants characteristic of 

 <i cold temperate region, and liable to meet with heavy snowfalls in the 

 winter months, can only escape destruction by special adaptation to such 

 conditions. The simplest way, apparently, is to become deciduous on 

 the approach of the cold season. Now, if we compare the characters of 

 the British and the New Zealand floras in this respect, we find an interest- 

 ing dissimilarity, which perhaps is b-ist shown by tabulating them as 

 follows : — 



Total number of species . . 

 Woody species 

 Evergreen trees and shrubs 

 Deciduous trees and shrubs 

 Leafless, or nearly so 



