Cpe 2) 
tive anatomist had occasion to speak or write on the broader 
aspects of biological inquiry.* 
Darwin also considered that there was something in the 
very conditions of domestication which tended to promote 
fertility between races and even between distinct species. 
Thus he followed Pallas in believing that the domestic dog 
has been derived from more than one wild species, although he 
did not trace existing differences to this cause but to artificial 
selection.t However, as regards the origin of the dog, “the 
evidence is, and must be, very doubtful,” as he wrote to Lyell, 
August 11, [1860]. The fact which Darwin “ considered the 
most remarkable as yet recorded with respect to the fertility of 
hybrids,” was the fertility of the offspring of the Common and 
Chinese Goose, originally described by Eyton, and confirmed by 
Goodacre and by Darwin himself. ‘The two species of goose 
now shown to be fertile inter se are so distinct that they have 
been placed by some authorities in distinct genera or sub- 
4 
genera.” { 
Another interesting and exceedingly difficult experiment in 
hybridisation has been carried through by the Rev. P. St. M. 
Podmore, F.Z.8., who in Sept. 1899, after numerous failures, 
succeeded in rearing a healthy male hybrid between the 
Ring Dove (Columba palumbus) and the domestic pigeon. 
On May 27, 1903, this male was mated with a Blue Homer 
hen, which produced healthy offspring. § 
* For several instances see Poulton’s ‘‘ Charles Darwin and the Theory 
of Natural Selection,” Lond. 1896, pp. 124-141. 
+ “Though I believe that our domestic dogs have descended from 
several wild forms, and though I must think that the sterility, which 
they would probably have evinced, if crossed before being domesticated, 
has been eliminated, yet I go but a very little way with Pallas & Co. in 
their belief in the importance of the crossing and blending of the 
aboriginal stocks. 
* * * * * * * 
* 
** Although the hound, greyhound, and bull-dog may possibly have 
descended from three distinct stocks, I am convinced that their present 
great amount of difference is mainly due to the same causes [artificial 
selection] which have made the breeds of pigeons so different from each 
other, though these breeds of pigeons have all descended from one wild 
stock ; so that the Pallasian doctrine I look at as but of quite secondary 
importance.” 
‘‘More Letters,” vol. i, pp. 127, 128, Letter 80, to Lyell, Oct. 31, 
[1859]. 
t ‘‘ Life and Letters,” vol. iii, p. 240. 
§ ‘‘The Zoologist,” Noy, 19038, p. 401. 
