402 Notices of Books. [July, 
should show but small tokens of friendship ? It is commonly 
supposed that the entire human race belongs to one and the 
same species, yet the mutual repulsion between certain of the 
ditferent strains of man is as well-pronounced as that between 
the dog and the fox. 
We may next notice certain passages extracted from a paper 
in the ninety-second number of the “ North British Review,” in 
which the dodtrine of Natural Selection is attacked from what 
may be called a mathematical point of view. We quote the 
passage: — “The advantage gained by one individual who has 
been favourably modified, is utterly overbalanced by numerical 
inferiority. A million creatures are born, ten thousand survive 
to produce offspring ; one of the million (from a favourable 
variation) has twice as good a chance as any other of surviving, 
but the chances are fifty to one against the gifted individual 
being one of the hundred survivors. No doubt the chances are 
twice as great against any other individual, but this does not 
prevent them from being enormously in favour of some average 
individual. All that can be said is that the favoured * sport ’ 
would be preserved once in fifty times. In the second place, let 
us consider what would be its influence on the main stock when 
preserved. It will breed and have a progeny of, say one 
hundred ; now this progeny will be, on the whole, intermediate 
between the average individual and the sport. The odds in 
favour of one of this generation will be, say, one-and-a-half to 
one as compared with the average individual. The odds in 
their favour will therefore be less than that of their parents, but 
owing to their greater number, the chances are that about one- 
and-a-half of them would survive. Unless these breed together, 
a most improbable event, their progeny would again approach 
the average individual, and so on until all trace of the original 
improvement disappeared.” 
“ Suppose a white man to have been wrecked on an island 
inhabited by negroes, and to have established himself in friendly 
relations with a powerful tribe whose customs he has learnt; 
grant him every advantage which we can conceive a white can 
have over a native, yet it does not follow that after an unlimited 
number of generations the inhabitants of the island will be white. 
Our shipwrecked hero might become king, he might kill a great 
many blacks in the struggle for existence, he could have a great 
many wives and children. In the first generation there will be 
dozens of young mulattos much superior in average intelligence 
to the negroes. We might expecft the throne to be occupied for 
some generations by a more or less yellow king, but can anyone 
believe that the whole island can gradually acquire a black or 
even a yellow population ? ” 
This extract is a very good instance of the quietly adroit 
manner in which mathematicians are apt to beg the question, 
and we regret to see that Mr. Maclaren has but a very remote 
