16 
POPULAR SCIENCE REVIEW. 
to the perpetual changes of surrounding circumstances, and 
keeps itself by its own variations in constant harmony with the 
ever-varying world around it. As earth and seas, forest, river 
and meadow, climate and temperature, are never for a moment 
stationary, but maintain a perpetual ebb and flow of ceaseless 
interchange, so the general forms and types of life, which are 
affected by all these influences, are also in continual and cor- 
responding flux. Both are always in a condition of instability 
in themselves, because both are always in perfect harmony 
with each other. But it follows from this that no modification 
can possibly be introduced into any form or type of life, unless 
it be beneficial to the creature modified — unless it tend, in some 
way or other, to bring him more into harmony with the condi- 
tions around him than he was before. If the change be merely 
a matter of indifference, doing neither good nor harm to the 
possessor, it will make no impression on the Kind. It is an 
individual peculiarity which may re-appear again here and there 
in other individuals, but which has no tendency to prevail over 
other similar peculiarities in others. But if the change is 
actually injurious, it will vanish at once. The unlucky pos- 
sessor of it will be inferior to his neighbours in the struggle 
for existence ; his life will be cut short sooner than that of 
others ; his offspring, if they inherit his peculiarity, will 
inherit also his disadvantages, and will soon perish out of the 
Kind, leaving no trace behind them. Natural selection is like 
fortune ; it favours only the brave ; it helps those only who 
can help themselves ; it rejects the weak, the puny, the ill- 
provided, and ill-adapted ; and its effect is best described as the 
survival of the fittest. 
Now let us apply these principles to the case of man. Were 
the changes by which the Kind passed — if it did pass — from 
some lower type to the human type such as would be mani- 
festly beneficial in the first instance to the individuals who 
were affected by these changes ? Because, if they were not, 
that transition could never have been effected by natural selec- 
tion. If it occurred at all, some other agency must be taken 
into account. What, then, were these changes ? We cannot, of 
course, tell exactly, unless we knew — as we certainly do not 
know — the form of life which immediately preceded the human. 
But let us assume for the moment that the anthropoid apes and 
man are the extremities of divergent lines from some remote 
ancestor, uniting in himself the characteristics which they have 
in common ; how would the differentiation begin to be carried 
on ? One of the most marked peculiarities in man is the soft, 
smooth skin. Alone among the mammalia, he is unprotected 
either by the hardness or the shagginess of his integument. He 
has neither the impenetrable armour of the rhinoceros, nor the 
