2(56 THE SPREAD OF EVOLUTION. [Ch. XIY. 



ledge of the action of artificial selection, we may well rejoice 

 that this subject was chosen by him for amplification. 



In 1864, he wrote to Sir Joseph Hooker : 



" I have begun looking over my old MS., and it is as fresh as 

 if I had never written it ; parts are astonishingly dull, but yet 

 worth printing, I think ; and other parts strike me as very good. 

 I am a complete millionaire in odd and curious little facts, and 

 I have been really astounded at my own industry whilst reading 

 my chapters on Inheritance and Selection. God knows when 

 the book will ever be completed, for I find that I am very weak, 

 and on my best days cannot do more than one or one and a half 

 hours' work. It is a good deal harder than writing about my 

 dear climbing plants." 



In Aug. 1867, when Lyell was reading the proofs of the book, 

 my father wrote : — 



" I thank you cordially for your last two letters. The former 

 one did me real good, for I had got so wearied with the subject 

 that I could hardly bear to correct the proofs, and you gave me 

 fresh heart. I remember thinking that when you came to the 

 Pigeon chapter you would pass it over as quite unreadable. I have 

 been particularly pleased that you have noticed Pangenesis. I 

 do not know whether you ever had the feeling of having thought 

 so much over a subject that you had lost all power of judging 

 it. This is my case with Pangenesis (which is 26 or 27 years 

 old), but I am inclined to think that if it be admitted as a 

 probable hypothesis it will be a somewhat important step in 

 Biology." 



His theory of Pangenesis, by which he attempted to explain 

 " how the characters of the parents are * photographed ' on the 

 child, by means of material atoms derived from each cell in 

 both parents, and developed in the child," has never met with 

 much acceptance. Nevertheless, some of his contemporaries 

 felt with him about it. Thus in February 1868, he wrote to 

 Hooker : — 



" I heard yesterday from Wallace, who says (excuse horrid 

 vanity), ' I can hardly tell you how much I admire the chapter 

 on Pangenesis. It is a positive comfort to me to have any 

 feasible explanation of a difliculty that has always been haunting 

 me, and I shall never be able to give it up till a better one 

 supplies its place, and that I think hardly possible.' Now 

 his foregoing [italicised] words express my sentiments exactly 

 and fully : though perhaps I feel the relief extra strongly from 

 having during many years vainly attempted to form some 

 hypothesis. When you or Huxley say that a single cell of a 

 plant, or the stump of an amputated limb, has the ' potentiality ' 



