In various ways the weakest are destroyed. Darwin, on a piece of ground three feet long and two wide, says, "I marked all the seedlings of our native weeds as they came up, and, out of 357, no less than 295 were destroyed, chiefly by slugs and insects."
He gives this interesting instance of the struggle for existence. "I find from experiments that humble-bees are almost indispensable to the fertilization of the heart's-ease, for other bees do not visit this flower.... Humble-bees alone visit red clover, as other bees cannot reach the nectar.... Hence we may infer as highly probable that, if the whole genus of humble-bees became extinct or very rare in England, the heart's-ease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great measure upon the number of field-mice, which destroy their combs and nests; the number of mice is largely dependent, as every one knows, on the number of cats." Hence, as Mr. Darwin shows, the frequency of certain flowers in a district may depend upon the number of cats!
Darwin showed, by most interesting experiments with pigeons, that the various breeds come from the wild rock-pigeon; that dogs are descended, probably, from the wolf; that different varieties can be produced and perpetuated under changing conditions of life; that species are only well marked and permanent varieties. He showed how organs can be changed by use or disuse; such as, the erect ears of wild animals become drooping under domestication; or moles have only rudimentary eyes, covered with skin or fur, because not needed for sight.
In the "Origin of Species," the theory of evolution received proof which was so nearly incontrovertible that the subject was brought prominently before the world as never before. Mr. Alfred Russell Wallace, an able scientist, came to the same conclusion as Darwin in regard to the power of "Natural Selection," and published, at the same time as the "Origin," an essay "On the Tendency of Varieties to depart indefinitely from the Original Type."
At once Darwin was attacked from every quarter. Probably not since Galileo showed that the earth moves round the sun has a man been so censured and persecuted for his opinions as was Darwin. He was declared atheistic, unsettling the Christian belief, and opposed to the teachings of the Bible. Professor Asa Gray of Cambridge, Mass., a devoted Christian and able scientist, defended and explained Darwin's views, now published in "Darwiniana," claiming that the doctrine of evolution is in no wise opposed to the power and goodness of the Almighty, and quotes Charles Kingsley's words: "We know of old that God was so wise that he could make all things; but behold, he is so much wiser than even that, that he can make all things make themselves." Kingsley wrote Darwin: "I have gradually learnt to see that it is just as noble a conception of Deity to believe that he created primal forms capable of self-development into all forms needful pro tempore and pro loco, as to believe that he required a fresh act of intervention to supply the lacunas which he himself had made. I question whether the former be not the loftier thought." Gray believed that "to do any work by an instrument must require, and therefore presuppose, the exertion rather of more than of less power than to do it directly." Darwin said, "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms, most beautiful and most wonderful, have been and are being evolved." Darwin always felt grateful to Asa Gray for his defence. He wrote him: "I declare that you know my book as well as I do myself; and bring to the question new lines of illustration and argument, in a manner which excites my astonishment and almost my envy!... I said, in a former letter, that you were a lawyer, but I made a gross mistake; I am sure that you are a poet. No, I will tell you what you are, a hybrid, a complex cross of lawyer, poet, naturalist, and theologian!"
Darwin wisely made no reply to his critics. He said, years later: "My views have often been grossly misrepresented, bitterly opposed and ridiculed, but this has been generally done, as I believe, in good faith. On the whole, I do not doubt that my works have been over and over again greatly overpraised. I rejoice that I have avoided controversies, and this I owe to Lyell, who, many years ago, in reference to my geological works, strongly advised me never to get entangled in a controversy, as it rarely did any good, and caused a miserable loss of time and temper.
"Whenever I have found out that I have blundered, or that my work has been imperfect, and when I have been contemptuously criticised, and even when I have been overpraised, so that I have felt mortified, it has been my greatest comfort to say hundreds of times to myself, 'that I have worked as hard and as well as I could, and no man can do more than this.'"
The "Origin" has been translated into French, German, Italian, Dutch, Russian, Swedish, and many other languages. Huxley says of it, "Even a cursory glance at the history of the biological sciences during the last quarter of a century is sufficient to justify the assertion that the most potent instrument for the extension of the realm of natural knowledge which has come into men's hands since the publication of Newton's 'Principia' is Darwin's 'Origin of Species.'"
The year after the "Origin" was published, Darwin began arranging his notes for his two large volumes, "Variation of Animals and Plants under Domestication," which, however, were not published till 1868. On these two books he spent over four years. They are a wonderful collection of facts, gathered from books and from his own marvellous experiments and observations, confirming and illustrating the law of "Natural Selection" given in the "Origin."
Darwin had already received the Copley medal of the Royal Society, the greatest honor a scientific man can receive in England, and the Prussian Order "Pour le Mérite," founded by Frederick II. The order consists of thirty German members and a few distinguished foreigners. In 1862 the "Fertilization of Orchids" was published, which, required ten months of labor. In this work Darwin took the utmost delight. He wrote to a friend who had sent him some of these flowers: "It is impossible to thank you enough. I was almost mad at the wealth of Orchids.... I never was more interested in any subject in my life than in this of Orchids." The peculiarities of the flowers therein described, as Darwin says, "transcend in an incomparable manner the contrivances and adaptations which the most fertile imagination of man could invent."