I 



Correnpondi-Hce laith Charles Darwin 161 



standing thix, I can awure you that I have the matter firmly in hand, and will be guided by 

 the reHults, iih to the extent of futiiro work. Dt'fihriniwHl hlixxl in my iialvation. I lit4;rHlly put 

 into my silver greys during one operation lui much liloo<l as I can get from two rahhitJt each of 

 the sanie »ize im the [mtieiit, and I have thre«i bucks who have undergone two operations (but 

 unluckily the earlier ones were fur loss .successful). Very sincerely yours, FRANCia Oaltok. 



(10) 43, Rutland Gatk, S.W. J,nu 2ftth, 1870. 



My dear Darwin, A curious and, it may \>e, very interesting result delays my transfusion 

 experiments. It is that 2, and 1 think all 3, of the does that had been couplwl with the largely 

 tninfiLsed Imeks prove alrrih'. Of course the sterility maj' Ik) due "to constitutioiukl shock, 

 or other minor matt^'fs, but, it mtgi/r^tn the iilea that the ivproductive elements are in the 

 portion of the bl<M><l which I diil not transfu.st^; —to wit tlw Jlbrim-. In my earlier experiments, 

 the blood WHS only partially dc('il)rini,se<l,— hence I wits able to get a white leg; but in those 

 later ones it wius wholly defibriiiised. It seems reasonable that the part of the bhxxl which 

 d(M's most in the i-epanition of injuries should also be most rich in the repro<luctive elementa. 

 Of course I go on with the experiments with modifications of procedure....! wish I ha<l more 

 to tell you. I have transfused into 32 rabbits, in six cases twice over.... 



Very sincerely yours, Francis Oalton. 



The letters now break off, uiid the Galtons went to Paris on July 15th, 

 intending to go to Switzerland ; they did go to Grindelwald, but the neclani- 

 tion of war between France and Prussia led them to return. Here, after a 

 stay at Folkestone, they paid visits to the Gurneys, at Julian Hill, at 

 Leamington and at the Groves, reaching London only on October 17th 

 (L. (j.'s Record). On Septemlier 27th, George Darwin, however, wrote that 

 his father sent his thanks for Galton's rabbit message and said that he was 

 deeply interested in the success of the experiment. The nature of that 

 experiment is clear, although Galton's letter detailing it appeJirs to have 

 perished; it is provided by Galton's pai)er itself; it wsis to cea.se defibrini- 

 sation, and it was done by establishing cro.s.s-circulation between the carotids, 

 the great arteries of the neck. 



"If the results were affirmative to the truth of Pangenesis, then my first experiments would 

 not be thrown away; for (supposing them to 1x3 contirnied by larger exp«>rience) they would 

 prove that the reproductive elements lay in the tibrine. But if cross-circulation gave a negative 

 reply, it would 1r> clear that the white ioot was an accident of no importance to the thtx)ry of 

 Pangenesis, and that the sterility need not be ascribed to the loss of here<litary gemmules, 

 but to abnormal health, due to detihrinisation and, perhaps, to other cau.ses also. 



My operations of crovss-circulation (which I call x) put me in posse-ssion of threi- excellent 



silver-grey bucks, and four excellent silver-grey does There were al.so three common rabbits, 



bucks, which were blood niat'es of silver-gi-eys, and four common rabbits, does, also blood mates 

 of silver-greys. From this large stock I have bretl eighty-eight rabbits in thirteen Iitt<'r8, and 

 in no single case has thei'e Ixmm> any evidence of alteration of breed. There has been one 

 instance of a sandy Himalaya ; but the owner of this breed assures me they are liable to throw 

 them, and lus a matter of fact, as I have alitsady stated, one of the does he sent me did litter 

 and throw one a few days after she reaclunl me. The conclusion from this large series of ex- 

 periments is not to be avoided, that the doctrine of Pangenesis, pure and simple, as I have 

 interpreted it, is incorrect." (p. 404, loe. cit.) 



Galton concludes that the gemmulea are not independent re-sitients in 

 the blood; they either reside in the sexual gland itself, the blmxl merely 

 forming nutriment to the growth, or they are merely temporary inhabitants 

 of the blood and rapidly perish, so that the transfu-sed gemmules |)erished 

 before the period elapsed when the animals had recovered from their opera- 

 tions. Galton suggests that an experiment might be made — as the animals 



i> a II SI 



