( 35) 
“ Dec, 18, [1862.] 
“Do you mean to say that Girtner lied, after experiments 
by the hundred (and he a hostile witness), when he showed 
that this was the case with Verbascum and with maize (and 
here you have selected races): does Kolreuter lie when he 
speaks about the varieties of tobacco? My God, is not the 
case difficult enough, without its being, as I must think, 
falsely made more difficult? I believe it is my own fault— 
my d d candour: I ought to have made ten times more 
fuss about these most careful experiments.” * 
“*T Jan. | 10, (1863. ] 
“Tn plants the test of first cross seems as fair as test of 
sterility of hybrids, and this latter test applies, I will maintain 
to the death, to the crossing of varieties of Verbascwm, and 
varieties, selected varieties, of Zea. You will say, Go to 
the Devil and hold your tongue. No, I will not hold my 
tongue; for I must add that after going, for my present 
book [Variation under Domestication], all through domestic 
animals, I have come to the conclusion that there are almost 
certainly several cases of two or three or more species blended 
together and now perfectly fertile together. Hence I 
conclude that there must be something in domestication,— 
perhaps the less stable conditions, the very cause which 
induces so much variability,—which eliminates the natural 
sterility of species when crossed. If so, we can see how 
unlikely that sterility should arise between domestic races. 
Now I will hold my tongue.” + 
Darwin made attempts to ‘produce physiological species 
by selection,” and thus meet his friend’s criticism. He 
thought out and suggested a plan of experiment to W. B. 
Tegetmeier,{ and gave a brief account of the scheme to 
Huxley, December 28, [1862]:—“TI have given him 
[Tegetmeier] the result of my crosses of the birds which he 
proposes to try, and have told him how alone I think the 
experiment could be tried with the faintest hope of suecess— 
namely, to get, if possible, a case of two birds which when 
* “More Letters,” vol. i, p. 230, Letter 156. 
+ Ibid. vol. i, pp. 231, 232, Letter 157. 
$ Ibid. vol. i, pp. 223, 224, Letter 153, [1862, Dec. | 27. 
