236 EVOLUTION IN NATURE AND UNDER DOMESTICATION. 



centre of gravity, and they walk with out-spread legs in a pe- 

 culiar shuffling way. Another remarkable variety, which is not 

 rarely seen in the East of Java, is represented by animals in 

 which all the feathers are reduced to bare shafts. It is certainly 

 remarkable that all these aberrations, together with the better 

 known ones, such as absence of tail, drooping-tail, foot-feathe- 

 ring, complete frizzling, occur where crossing with Varius takes 

 place. We would not be understood to say, that we believe that 

 the tame chickens descend from hybrids between bankiva and 

 varius, from Bekisars, and we would not hesitate to call the 

 tame fowl Gallus bankiva hybrida. As we see the facts, we 

 would say that the tame fowls are descended from domestica- 

 ted Gallus bankiva, the potential variability of which was, and 

 is still heightened by taking up of hybrids with varius and not 

 impossibly with other wild fowls into the species. 



The second domestic animal for which Darwin assumed mon- 

 ophyletic origin is the pigeon. We have to concede Darwin 

 that all tame pigeons have several characters in common with 

 Columba livia and that no other wild pigeon exists which 

 would be more likely to be the progenitor of all tame breeds. 

 Here, as in the fowl, we need not look for wild species showing 

 the various characters of domestic breeds, but, as in the fowl, 

 we may assume that the necessary variability in pigeons was, 

 and probably still is, produced by cross-breeding with other 

 species, if we can find instances of hybrids which produce fer- 

 tile offspring when mated to domestic pigeons. We do not need 

 to restrict our search to the species which nest in cavities, 

 as Darwin believed. For it is clear, that the descendants of hy- 

 brids with a species nesting in trees, which would have a geno- 

 type compelling them to nest in trees, would automatically get 

 weeded out of the population. Mr. Podmore has shown that 

 hybrids between the European Woodpigeon, Columba oenas, 

 and tame pigeons can be bred back to tame pigeons. Therefore, 

 we can at least look to this species as to one of those, that can 

 have given the great variability in domestic pigeons. It may 

 look strange to assume that the ultimate origin of such aber- 



