iS62 EDINBURGH LECTURES ON MAN 21I 



ing the weight of the hybrid difficulty. All this will be put fully 

 when I print the Lecture. 



The arguments put in your letter are those which I have 

 urged to other people — of the opposite side — over and over 

 again. I have told my students that I entertain no doubt that 

 twenty years' experiments on pigeons conducted by a skilled 

 physiologist, instead of by a mere breeder, would give us 

 physiological species sterile inter se, from a common stock (and 

 in this, if I mistake not, I go further than you do yourself), 

 and I have told them that when these experiments have been 

 performed I shall consider your views to have a complete 

 physical basis, and to stand on as firm ground as any physio- 

 logical theory whatever. 



It was impossible for me, in the time I had, to lay all this 

 down to my Edinburgh audience, and in default of full ex- 

 planation it was far better to seem to do scanty justice to you. I 

 am constitutionally slow of adopting any theory that I must 

 needs stick by when I have once gone in for it; but for these 

 two years I have been gravitating towards your doctrines, and 

 since the publication of your primula paper with accelerated 

 velocity. By about this time next year I expect to have shot 

 past you, and to find you pitching into me for being more Dar- 

 winian than yourself. However, you have set me going, and 

 must just take the consequences, for I warn you I will stop at 

 no point so long as clear reasoning will carry me further. 



My wife and I were very grieved to hear you had had such 

 a sick house, but I hope the change in the weather has done you 

 all good. Anything is better than the damp warmth we had. 



I will take great care of the three " Barriers." * I wanted to 

 cut it up in the Saturday, but how I am to fulfil my benevolent 

 intentions — with five lectures a week — a lecture at the Royal 

 Institution and heaps of other things on my hands, I don't know. 

 — Ever yours faithfully, T. H. Huxley. 



I am very glad to hear about Brown Sequard ; he is a thor- 

 oughly good man, and told me it was worth while to come all 

 the way to Oxford to hear the Bishop pummelled. 



In the above-mentioned letter to the Scotsman of Janu- 

 ary 24 he expresses his unfeigned satisfaction at the fulfil- 



* A pamphlet called "The Three Barriers, by G. R., being notes 

 on Mr. Darwin's Origin of Species, 1861, 8vo," Habitat, structure, and 

 procreative power are given as these three barriers to Darwinism, 

 against which natural theology takes its stand on Final Causes. 



