INTRODUCTION, AXV 
and Maui the vegetation of the lower and part of the middle 
forest-zones is dwarfed; there are no trees properly speaking, 
everything is low shrub, stunted and gnarled, with stiff branches, 
the leaves crowded at their ends or in distant whorls, coriaceous, 
and generally tomentose underneath. The great heat and dryness of 
the air, the scanty soil — often undecomposed lava — check 
life. Short seasons of growth follow the rare rainfalls, to be 
succeeded by long periods of repose. As a rule the trees ‘growing 
here have some peculiarity of their own which distinguishes them 
as varieties from the species of the same genus growing in the 
forests above. These regions look like the Australian Scrub or 
Californian Chaparal. In the following pages I have adopted 
the Australian name to designate it. There is a good deal of 
it also on Lanai, which lies under the cover of Eeka, and much 
less on Molokai. The vegetation of the third forest-zone on the 
high central plateau of Hawaii is of the same character, but 
composed of different species 
A comparison of the Hawaiian flora with that of any other 
country brings out at once a striking difference in the great 
number of varieties in all the species of leading genera. Some 
of these varieties are limited to narrow localities, and many of 
them might claim to rank as species. Others are spread over 
several islands and seem to be the product of climatal peculiarities, 
the same condition calling forth similar deviation from the nor- 
mal type. Thus, in the scrub vegetations of the lee sides, the 
arid rocky soil, intense light and rare rainfalls, and rest of growth 
tance, for not rarely the same variety occurs above and below 
the dense forest-zone. The species are in consequence not well 
defined, and their description will be found to suffer from want 
of brevity, of terseness, which the student is inclined to ex 
in a work of this kind. As an apology I can only plead that 
my constant endeavor has been to be faithful to nature, that 
I have thought necessary in order to bring out the general 
transitions from one form to another to enter upon characters 
which often are considered of small importan ce. 
Nature here luxuriates in formative energy. Is it because 
the Islands offer a great range of conditions of life? Or is it 
because the leading genera are in their age of manhood, of 
