XIV 
FUNDAMENTAL PROBLEMS 
433 
and with our very limited number of trees and shrubs we 
have about eighteen spiny or prickly species, more, apparently, 
than in the whole endemic floras of the Mauritius, Sandwich 
Islands, and Galapagos, though these are all especially rich 
in shrubby and arboreal species. In New Zealand the prickly 
Eubus is a leafless trailing plant, and its prickles are probably 
a protection against the large snails of the country, several of 
which have shells from two to three and a half inches long. 1 
The “wild Spaniards” are very spiny herbaceous Umbelliferse, 
and may have gained their spines to preserve them from being 
trodden down or eaten by the Moas, which, for countless ages, 
took the place of mammals in New Zealand. The exact use 
or meaning of the spines in palms is more doubtful, though 
they are, no doubt, protective against some animals ; but it is 
certainly an extraordinary fact that in the entire flora of the 
Mauritius, so largely consisting of trees and shrubs, not a 
single endemic species should be thorny or spiny. 
If now we consider that every continental flora produces 
a considerable proportion of spiny and thorny species, and that 
these rise to a maximum in South Africa, where herbivorous 
mammalia were (before the settlement of the country), perhaps, 
more abundant and varied than in any other part of the 
world; while another district, remarkable for well-armed 
vegetation, is Chile, where the camel-like vicugnas, llamas, and 
alpacas, and an abundance of large rodents wage perpetual 
war against shrubby vegetation, we shall see the full signifi¬ 
cance of the almost total absence of thorny and spiny plants in 
the chief oceanic islands; and so far from “ excluding the 
hypothesis of mammalian selection altogether,” we shall find 
in this hypothesis the only satisfactory explanation of the 
facts. 
From the brief consideration of Professor Geddes’s theory 
now given, we conclude that, although the antagonism between 
vegetative and reproductive growth is a real agency, and must 
be taken account of in our endeavour to explain many of the 
fundamental facts in the structure and form of plants, yet it 
is so overpowered and directed at every step by the natural 
selection of favourable variations, that the results of its 
1 Placostylis bovinus, 3b inches long ; Paryplianta Busbyi, 3 in. diam. ; 
P. Hochstetteri, 2J in. diam. 
