General Conclusions. 323 
now difhicult to disentangle. They have this one property in common, the 
power, for the most part to endure a fair amount of cold.‘) In other words, 
the element is a temperate one 
The second elemient, also largely endemic, consists of descendents of an 
ancient palaeotropic stock, so ancient indeed that endemic genera have been 
® developed (Rhabdothamnus, Ixerba, Alectryon &c.), as well as A distinct 
- endemic species. 
Yet notwithstanding this great age of the members, and their long iso- 
lation far from the tropics, but few have become really fitted to the present 
average climate of New Zealand, in fact the majority can tolerate very little 
frost. For the most part, the species of this class are confined to the lowlands, 
and in the 5. some are only found near the coast. This element, in fact, is 
eminently subtropical; so that the present-day climate is one to which it is 
not perfectly attuned?). Should a change of climate occur, then with increase 
ot temperature the palaeotropic element would advance southwards and the 
palaeozelandic -subantarctic retreat to the mountains, while, with increase of 
cold, the contrary would be the case. The BR one of Nothofagus =» 
Be. ee in the North Auckland district, point to such a change of climate, while | 
the presence of the tree-fern Hemitelia Smithii in the Lord Auckland’s district 
suggests a warmer period. But apart from speculations, the non-toleration of 
frost by so many New Zealand species is good evidence that there has either 
been a considerable northern land-extension during the glacial period or ER 
that such did not owe its origin even, in part, to increase of co 
It has been shown that while there is a considerable Kusiräkien element, 
it is made up largely of Subantarctic and Palaeotropic species, while the true 
Australian element does not play a conspicuous part in the vegetation. 
Especially is the absence of characteristic Australian genera noteworthy, ı eg i 
— Eucalyptus, Acacia &c., although virtually all the Tasmanian species s are 
not only quite hardy in the warmer parts of New Zar but some can 
spread spontaneousiy. Bearing these facts in mind, sibility 
land-connection with essebser gie: except . at a 8 
entertained. 
ı) Nevertheless they are, generally speaking, er amanle. to tolerate co 
of Central Europe. 
2) For example Corps riet is killed. during & speiiy ee wien 
