We would naturally follow the advice of such high authorities on the use of words connected with the theory of which they are such eminent exponents; but one pauses reluctantly to ask, why should the term Natural Selection be more convenient or equally convenient if the phrase "survival of the fittest" be more accurate? In what can the convenience of the less accurate consist, and to whom is it more convenient to be less accurate?

If we were dealing with ordinary men, and not with the greatest scientist and the greatest philosopher of the nineteenth century, it would be possible to find an answer to this question. We should say that having two inaccurate, rhetorical, unscientific phrases, it was eminently convenient to have a choice; so that when a doubt was raised as to the "survival of the fittest," we might talk about "Natural Selection," and when we were in difficulty as to "Natural Selection," we might use the phrase "survival of the fittest."

CHAPTER III.

DIFFICULTIES INHERENT IN THE THEORY.

"Lest men suspect your tale untrue,
Keep probability in view."- GAY.

THERE are certain difficulties in connection with this theory which meet us on the very threshold of the enquiry; inasmuch as they are inherent in the theory itself. This is certainly not what we should expect to find.

In the first place, it strikes one as rather startling that the transmutation of species by means of Natural Selection can only come into action in the face of adverse changes. For this process of transmutation starts from the point where a species has become adapted to its external conditions. Now if the conditions, though changing in detail, are nevertheless equally favourable to the race, it is obvious that no modification can be wrought by Natural Selection, for no change would then be useful to the race. If altered conditions were still more favourable than the old ones, there would be still less need for any responsive adaptation. It is, therefore, only in the face of adverse circumstances which make modification a necessity-a matter of life and death-that Natural Selection can come upon the scene. Disastrous change is the overture to the opera: the prologue to the play.

These changes must not be too rapid or the organisms would perish they must not be too mild or they would not involve a question of life and death, i.e., they would not bring Natural Selection into action. The theory

demands just the right amount of adverse circumstances which shall not exterminate, on the one hand, and which shall not fall short of a life-and-death severity on the other hand. This is surely a large demand to make on natural phenomena to start with.

But, in the second place, in this time of danger, in this critical period in the history of the race, it is most important that Natural Selection should act with promptitude. But here another difficulty occurs. Like Mr. Micawber it has to wait for favourable variations "to turn up;" and with respect to the emergence of these favourable variations Natural Selection is precisely analogous to a game of pure chance. In this sense it is perfectly true to say—

"The origin of mimetic coloration, like many other things, is yet unknown. An orthodox Darwinian attributes it to Natural Selection, which turns out on analysis to be hazard. The survival of useful coloration is no doubt the result of Natural Selection."(Cope. The Origin of the Fittest. p. 410.)

"On the Darwinian hypothesis, man is the child of Chance ; as from the Evolution hypothesis, in its full generality, all life is the result of Chance."-(Graham. The Creed of Science. p. 27.)

If this be so, it is obvious that Natural Selection is heavily handicapped. We are not surprised, therefore, to find that the advocates of Natural Selection have repudiated with scorn the idea that Natural Selection has anything to do with chance.

Professor Huxley says:

"But there are two or three objections of a more general character, based, or supposed to be based, upon philosophical and theological foundations, which were loudly expressed in the early days of the Darwinian controversy, and which, though they have been answered over and over again, crop up now and then at the present day.

"The most singular of these, perhaps immortal, fallacies, which live on, Tithonus-like, when sense and force have long deserted them, is

that which charges Mr. Darwin with having attempted to reinstate the old pagan goddess, Chance. It is said that he supposes variations to come about by chance,' and that the fittest survive the chances of the struggle for existence, and thus 'chance' is substituted for providential design.”—(Life and Letters of Darwin. vol. ii., p. 199.)

It must be confessed that this subject is beset with no little difficulty; for if it is contended-as Pfaffer Kneipp does contend-that chance is in reality "a vague and nonsensical word, because there is no such thing as chance," we ask in perplexity-Is there no such thing as a "game of chance?" There must be some sense in which that phenomenon, which has ruined so many, is a reality.

Some definitions throw very little light upon the subject. Dr. Johnson, for example, defines chance as the cause of fortuitous events, which leaves me, at any rate, about as wise as I was before, because I am still anxious to know what "fortuitous" means! It seems to me very much like defining an archdeacon as a clergyman who performs archidiaconal functions.

But Mr. Huxley asserts that Mr. Darwin has defined the sense in which he wishes the word chance to be understood.

"It is not a little wonderful that such an accusation as this should be brought against a writer who has, over and over again, warned his readers that when he uses the word 'spontaneous,' he merely means that he is ignorant of the cause of that which is so termed, and whose whole theory crumbles to pieces if the uniformity and regularity of natural causation for illimitable past ages is denied.”—(Life and Letters. ii., p. 199.)

But when the opponent of Natural Selection is charged with forgetting that Mr. Darwin has defined a spontaneous phenomenon as one which occurs in connection with a law

of whose action we are ignorant, the accuser should remember that Mr. Darwin himself uses chance in three different senses. He says:

. to ask

"I was so convinced that not even a stripe of colour appears from what is commonly called chance, that I was led Colonel Poole whether such face stripes ever occurred in the eminently striped Kattywar breed of horses, and was answered in the affirmative."-(Origin of Species. p. 129.)

Here he understands by chance "what happens without necessary cause."

Again, when he explains that in using the word spontaneous he only means to assert his ignorance of the nature of the cause, in whose existence he firmly believes, he adopts another definition of cause, viz.: "what happens through a definite law, concerning the action of which we are ignorant."

But there is a third sense in which Mr. Darwin uses the word chance.

"In all the foregoing cases, the insects, in their original state, no doubt presented some rude and accidental resemblance to an object commonly found in the stations frequented by them."-(Origin of Species. p. 182.)

Here he adopts the definition of chance, which regards. it as the coincidence of two sets of phenomena which have been produced by the definite action of the laws of nature.

"Chance is the combination of several systems of causes which are developed each in its own series independently of the others."

"All the phenomena of nature are linked in the bond of cause and effect; but all these phenomena do not form a single indefinite chain in which each phenomenon would come to occupy a place in its turn, and where there would only be room for a single phenomenon at a time. No! at one and the same moment there is an infinite number of phenomenal series which take place at all points of the globe and of the universe. These simultaneous phenomenal series are sometimes parallel and sometimes oblique. Representing these phenomenal series by lines, the points where they meet are points of coincidence.