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the extermination of the less fit and the survival of the 
more fit of the two competitors. Mr. Romanes says :— 
“ First, it is a matter of observation that the struggle for existence 
in nature does lead to the extermination of forms less fitted for the 
struggle, and thus makes room for forms more fitted. This general 
fact may be best observed in cases where an exotic species proves 
itself better fitted to inhabit a new country than is some endemic 
species which it exterminates. In Great Britain, for example, the so- 
called common rat is a comparatively recent importation from Norway, 
and it has so completely supplanted the original British rat, that it is 
now extremely difficult to procure a single specimen of the latter : 
the native black rat has been all but exterminated by the foreign 
brown rat. The same thing is constantly found in the case of 
imported species of plants. I have seen the river at Cambridge so 
choked with the inordinate propagation of a species of water-weed 
which had been introduced from America, that considerable expense 
had to be incurred in order to clear the river for traffic. In New 
Zealand the same thing' has happened with the European watercress, 
and in Australia with the common rabbit. So it is doubtless true, as 
one of the natives is said to have philosophically remarked, ‘ the 
white man’s rat has driven away our rat, the European fly drives 
away our fly, his clover kills our grass, and so will the Maoris 
disappear before the white man himself.’ Innumerable other cases 
to the same effect might be quoted, and they all go to establish the 
fact that forms less fitted to survive succumb in their competition 
with forms better fitted.”—(Romanes. Darwin and After Darwin. 
PP- 285-6.) 
In asserting that the victory of one race over another 
is a strong argument for the theory of Natural Selection, 
Mr. Romanes is merely maintaining the position taken by 
Mr. Darwin. The very title of Mr. Darwin’s great work, 
The Origin of Species by means of Natural Selection, 
or the Preservation of Favoured Races in the Struggle 
for Life, implies that the victory of one race over another 
is Natural Selection. And the implication is emphasised 
in the body of the work, where he contends that “the 
theory of Natural Selection is grounded on the belief that 
each new variety, and ultimately each new species, is pro 
duced and maintained by having some advantage over