1858.] THE LETTER TO DR. GRAY. 121 



ungrateful if your letters to me, and all I have heard of you, 

 had not strongly enhanced this feeling. But I did not feel in 

 the least sure that when you knew whither I was tending, 

 you might not think me so wild and foolish in my views (God 

 knows, arrived at slowly enough, and I hope conscientiously), 

 that you would think me worth no more notice or assistance. 

 To give one example : the last time I saw my dear old friend 

 Falconer, he attacked me most vigorously, but quite kindly, 

 and told me, " You will do more harm than any ten Naturalists 

 will do good. I can see that you have already corrupted and 

 half-spoiled Hooker ! ! " Now when I see such strong feeling 

 in my oldest friends, you need not wonder that I always ex- 

 pect my views to be received with contempt. But enough and 

 too much of this. 



I thank you most truly for the kind spirit of your last letter. 

 I agree to every word in it, and think I go as far as almost 

 any one in seeing the grave difficulties against my doctrine. 

 With respect to the extent to which I go, all the arguments 

 in favour of my notions fall rapidly away, the greater the scope 

 of forms considered. But in animals, embryology leads me to 

 an enormous and frightful range. The facts which kept me 

 longest scientifically orthodox are those of adaptation the 

 pollen-masses in asclepias the mistletoe, with its pollen 

 carried by insects, and seed by birds the woodpecker, with 

 its feet and tail, beak and tongue, to climb the tree and secure 

 insects. To talk of climate or Lamarckian habit producing 

 such adaptations to other organic beings is futile. This diffi- 

 culty I believe I have surmounted. As you seem interested 

 in the subject, and as it is an immense advantage to me to 

 write to you and to hear, ever so briefly, what you think, 

 I will enclose (copied, so as to save you trouble in reading) 

 the briefest abstract of my notions on the means by which 

 Nature makes her species. Why I think that species have 

 really changed, depends on general facts in the affinities, 

 embryology, rudimentary organs, geological history, and geo- 



