Correspondence with Charles Darwin 187
relationship, than in much current literature. It is only the terminology and the fact that Galton was not a professional biologist which have deprived him of the credit due to him as the discoverer or inventor of what we now term the `continuity of the germ-plasm.' Might not that theory, Galton modestly suggests, be substituted with advantage for that of pangenesis?
DowN, Nov. 7th .
MY DEAR GALTON, I have read your essay with much curiosity and interest, but you probably have no idea how excessively difficult it is to understand. I cannot fully grasp, only here and there conjecture, what are the points on which we differ-I daresay this is chiefly due to muddle-headiness on my part, but I do not think wholly so. Your many terms, not defined "developed germs"-"fertile" and "sterile" germs (the word `germ' itself from association misleading to me), "stirp,"-"sept," "residue" etc. etc., quite confounded me. If I ask myself how you derive and where you place the innumerable gemmules contained within the spermatozoa formed by a male animal during its whole life I cannot answer myself. Unless you can make several parts clearer, I believe (though I hope I am altogether wrong) that very few will endeavour or succeed in fathoming your meaning. I have marked a few passages with numbers, and here make a few remarks and express my opinion, as you desire it, not that I suppose it will be of any use to you.
(1) If this implies that many parts are not modified by use and disuse during the life of the individual, I differ from you, as every year I come to attribute more- and more to such agency.
(2) This seems rather bold, as sexuality has not been detected in some of the lowest forms, though I daresay it may hereafter be.
(3) If gemmules (to use your own term) were often deficient in buds I could but think the bud-variations would be commoner than they are in a state of nature; nor does it seem that bud-variations often exhibit deficiencies which might be accounted for by absence of the proper gemmules. I take a very different view of the meaning or cause of sexuality.
(4) I have ordered Fraser's Mag. and am curious to learn how twins from a single ovum are distinguished from twins from 2 ova. Nothing _seems to me more curious than the similarity and dis-similarity of twins.
(5) Awfully difficult to understand.
(6) I have given almost the same notion.
(7) I hope that all this will be altered. I have received new and additional cases, so that I have now not a shadow of doubt.
(8) Such cases can hardly be spoken of as very rare, as you would say if you had received half the number of cases which I have.
I am very sorry to differ so much from you but I have thought that you would desire my open opinion. Frank is away; otherwise he should have copied my scrawl.
I have got a good stock of pods of Sweet Peas, but the autumn has been frightfully bad; perhaps we may still get a few more to ripen.
My dear Galton, Yours very sincerely, Cn. DARwiN.
A. R. Wallace took a different view as to what Galton had achieved in a letter of the following spring.
THE DELL, GRAYS, EssEx. March 3rd, 1876.
DEAR MR GALTON, I return your paper signed. It is an excellent proposal. I must take the opportunity of mentioning how immensely I was pleased and interested with your-last papers in the Anthrop. Journal. Your 'Theory of Heredity' seems to me most ingenious and a decided improvement on Darwin's, as it gets over some of the great difficulties of the cumbrousness of his Pangenesis. Your paper on Twins is also wondrously suggestive.
Believe me, Yours very faithfully, ALFRED-R. WALLACE.
F. GALTON, Esq.