Editing Pangenesis (section)

=== Galton's experiments on rabbits ===
Darwin's half-cousin [[Francis Galton]] conducted wide-ranging inquiries into heredity which led him to refute Charles Darwin's hypothetical theory of pangenesis. In consultation with Darwin, he set out to see if gemmules were transported in the blood. In a long series of experiments from 1869 to 1871, he transfused the blood between dissimilar breeds of rabbits, and examined the features of their offspring. He found no evidence of characters transmitted in the transfused blood.<ref>{{cite book |last=Bulmer |first=Michael G. |title=Francis Galton : pioneer of heredity and biometry |publisher=Johns Hopkins University Press |publication-place=Baltimore, Md. |date=2003 |isbn=978-0-8018-8140-4 |oclc=559350911 |pages=116–118}}</ref>

[[Francis Galton|Galton]] was troubled because he began the work in good faith, intending to prove Darwin right, and having praised pangenesis in ''Hereditary Genius'' in 1869. Cautiously, he criticized his cousin's theory, although qualifying his remarks by saying that Darwin's gemmules, which he called "pangenes", might be temporary inhabitants of the blood that his experiments had failed to pick up.{{sfn|Browne|2002|p=291–292}}

Darwin challenged the validity of Galton's experiment, giving his reasons in an article published in ''Nature'' where he wrote:<ref name=Darwin1871>{{cite journal |author=Darwin, Charles R. |author-link=Charles Darwin |date=27 April 1871 |url=http://darwin-online.org.uk/content/frameset?itemID=F1751&viewtype=side&pageseq=1 |title=Pangenesis |journal=Nature |volume=3 |issue=78 |pages=502–503 |doi=10.1038/003502a0 |bibcode=1871Natur...3..502D |doi-access=free }}</ref>

{{blockquote |Now, in the chapter on Pangenesis in my ''Variation of Animals and Plants under Domestication,'' I have not said one word about the blood, or about any fluid proper to any circulating system. It is, indeed, obvious that the presence of gemmules in the blood can form no necessary part of my hypothesis; for I refer in illustration of it to the lowest animals, such as the Protozoa, which do not possess blood or any vessels; and I refer to plants in which the fluid, when present in the vessels, cannot be considered as true blood." He goes on to admit: "Nevertheless, when I first heard of Mr. Galton's experiments, I did not sufficiently reflect on the subject, and saw not the difficulty of believing in the presence of gemmules in the blood.<ref name=Darwin1871/>}}

After the circulation of Galton's results, the perception of pangenesis quickly changed to severe skepticism if not outright disbelief.<ref name=":4"/>