190 
particularize species, which might easily he done to any extent), and 
that the cliief cause to which this is to be attributed is the 
introduction by man of creatures more fitted to carry on the battle of 
life, Avhich the presence of the interlopers necessitates, than the 
indigenous species which for ages have led a peaceful life, the only 
competition to which they have been subject being from creatures 
of like organization to themselves. To use the words of Professor 
hs’ewton in his address to the Biological Section of the British 
Association, at Glasgow in 187G, when they are brought “face to face 
with unlooked-for invaders, and forced into a contest with them 
from which there is no retreat, it is not in the least surprising that 
the natives should succumb. They have hitherto had to struggle 
for existence with creatures of a like organization, and so for 
centuries may have kept the noiseless tenor of their way. 
Suddenly man interferes, and lets loose upon them an enthely new 
race of animals, which act and react in a thousand different fashions 
on their circumstances. It is not necessary that the new-comers 
should be predaceous ; they may so far avoid offence as to abstain 
from assaulting the aboriginal population ; but they occupy the 
same haunts and consume the same food. The fruits, the herbage, 
and other sujrplies, that siifficed to sujiport the ancient fauna, have 
now to furnish forage for the invaders as well. The struggle is 
like one between an army of veterans and a population not used 
to warfare. It is that of Spaniards with matchlocks and coats of 
mail, against Aztecs with feather- cloaks and arrows. A few years 
and the majority of native species are exterminated. But this is 
not the worst. The species which perish most quickly are just those 
which naturalists would most wish to preserve ; for they are those 
peculiar and endemic forms that in structure and constitution repre- 
sent the ancient state of things upon the earth, and supply us with 
some of the most instructive evidences as to the order of nature.” 
Professor hlewton, in the passage which I have just quoted, was 
referring to the animal kingdom, but his remarks apply with equal 
force to the vegetable world. Tliis is remarkably exemplified in 
the flora of the Island of St. Helena. Mr. St. John Mivart, in the 
‘ (Mutemporary Eeview ’ for April, 1880 (p. G17), states that when 
discovered by the Portuguese in 1502 that island was covered with 
luxuriant forests and a rich flora of absolutely peculiar plants. In 
1513 Goats were introduced, which rapidly multiplied, greatly to 
