THE PASSING OF DARWINISM, 



47 



THE PASSING OF DARWINISM. 

 By Rev. Prof. G. Henslow, M.A., F.L.S., V.M.H. &c. 



[Read March 16, 1915 ; Dr. F. Keeble, F.R.S., in the Chair.] 



Introduction. — Darwinism, or the Theory of the Origin of Species 

 by means of Natural Selection, has held its ground for fifty-five years. 

 But it is destined to pass away ; though the " struggle for existence " 

 with the " survival of the fittest " upon which the theory was based 

 will continue, presumably, amongst living organisms, as long as the 

 world shall exist. The theory itself cannot last, though Evolution is 

 now based on far securer grounds than Darwin could realize in the 

 fifties. It is established on a vast amount of induction and experi- 

 mental verification ; but the origination of varieties and species has 

 nothing to do with either the struggle for existence or natural selection, 

 for organisms create their own adaptive variations of structure by 

 responding directly to changed conditions of life. 



Mr. Bateson said in his address, as President of the British 

 Association at the meeting held at Melbourne (1914) : — " We have come 

 to the conviction that the principle of ' natural selection ' cannot have 

 been the chief factor in delimiting the species of animals and plants. . . . 

 We are even more sceptical as to the validity of that appeal to changes 

 in the conditions of life, as direct causes of modification, upon which 

 latterly, at all events, Darwin laid much emphasis." 



My object in this lecture is to show that as far as the first part of 

 this quotation is concerned Mr. Bateson is right ; but with the second 

 he has no grounds for being sceptical, as I shall prove in this and my 

 next lecture. 



What, then, does " Darwinism " mean ? It is a word expressing 

 Darwin's theory, called " The Origin of Species by means of Natural 

 Selection," the title of his book published in 1859. 



Let us briefly trace the progress in Darwin's mind, and see how the 

 theory arose to account for the " transmutation of species " through 

 r delimitation " (not their " origin ") by means of " natural selection." 



1833-1837, Origin of the Idea of " Transmutation of Species." — ■ 

 Darwin's first conception of the origin of species by " transmutation " 

 arose in his mind in 1835 when he visited the Galapagos Archipelago, 

 situated in the Pacific Ocean, near the Equator, about 550 miles or so 

 from South America. He had made a previous discovery of gigantic 

 fossils in South America, when at Bahia Blanca in 1833 ; which, though 

 now extinct and of enormous size, are represented at the present day by 

 the small Sloth, the Armadillo, and the Ant-eater, of the same family. 

 In the Galapagos Islands he discovered the existing plants and 

 animals to be of the same genera as those of South America ; but the 



