[What, then, were the facts which justified so great a change as had taken place, which had removed some of the most important qualifications under which he himself had accepted the theory?  He proceeded to enumerate the] “crushing accumulation of evidence” [during this period, which had proved the imperfection of the geological record; had filled up enormous gaps, such as those between birds and reptiles, vertebrates and invertebrates, flowering and flowerless plants, or the lowest forms of animal and plant life.  More:  paleontology alone has effected so much—­the fact that evolution has taken place is so irresistibly forced upon the mind by the study of the Tertiary mammalia brought to light since 1859, that] “if the doctrine of evolution had not existed, paleontologists must have invented it.” [He further developed the subject by reading before the Zoological Society a paper “On the Application of the Laws of Evolution to the Arrangement of the Vertebrata, and more particularly of the Mammalia” ("Proceedings of the Zoological Society” 1880 pages 649-662).  In reply to Darwin’s letter thanking him for the “Coming of Age” ("Life and Letters” 3 24), he wrote on May 10:—­]

My dear Darwin,

You are the cheeriest letter-writer I know, and always help a man to think the best of his doings.

I hope you do not imagine because I had nothing to say about “Natural Selection,” that I am at all weak of faith on that article.  On the contrary, I live in hope that as paleontologists work more and more in the manner of that “second Daniel come to judgment,” that wise young man M. Filhal, we shall arrive at a crushing accumulation of evidence in that direction also.  But the first thing seems to me to be to drive the fact of evolution into people’s heads; when that is once safe, the rest will come easy.

I hear that ce cher X. is yelping about again; but in spite of your provocative messages (which Rachel retailed with great glee), I am not going to attack him nor anybody else.

[Another popular lecture on a zoological subject was that of July 1 on “Cuttlefish and Squids,” the last of the “Davis” lectures given by him at the Zoological Gardens.

More important were two other essays delivered this year.  The “Method of Zadig” ("Collected Essays” 4 1), an address at the Working Men’s College, takes for its text Voltaire’s story of the philosopher at the Oriental court, who, by taking note of trivial indications, obtains a perilous knowledge of things which his neighbours ascribe either to thievery or magic.  This introduces a discourse on the identity of the methods of science and of the judgments of common life, a fact which, twenty-six years before, he had briefly stated in the words,] “Science is nothing but trained and organised common sense” [("Collected Essays” 3 45).