1 92 1.] and their part in Evolution. 725 



b}^ no moans unknown ; or agiiin, cheqnerino, a cliaractcr 

 common to some domestic Pigeons but prol)ably unknown 

 in the pure wikl Rock-Pigeon, is found in a few wikl species 

 of Pigeon — e.<j. the Guinea Pigeon of Africa, and so on. 



I am quite in agreement with Colonel Meinertzhagcn that 

 a mutation cannot establish a subspecies, since to mymnid a 

 subspecies is entirely an environmental or geographic form ; 

 and if my reasoning in the earlier part of this paper bo 

 correct, a geogra[)hic form could never become a separate 

 species. It might, I conceive, be possible for some factor to 

 become " latent " or lost throuoli a chano-e in the environ- 

 ment, and then a new species would evolve. 8ueh an event 

 might, by some, be termed a mutation (it would probably 

 follow a Mendelian inheritance), but that is a debatable 

 subject on which I will not venture at present. 



Putting the above case on one side and ouiitting dimor[)hic 

 forms which possibly fall in the above category, have we 

 any definite knowledge of a new species originatiug as a 

 mutation ? Omitting Favo nl(_/ri]>i'nnis, which has not, I 

 believe, occurred in a wild state, I can only recall the Italian 

 Little Owl, Athene chiaradia' (Giglioli, Ibis, 1901'), p. 1); but 

 unfortunately, although this sport was found in one or two 

 places and seemed to be on the increase, it was collected for 

 museums, and thus an unique chance of getting evidence on 

 this })rol)loin was lost. 



In putting forward these views, I do not claim that they 

 are in any way indisputable or final, nor has it been my 

 object to ])Our destructive criticism on the observations and 

 thoughts of the previous writers ; but they havc^ been written 

 in the hope that some of the energies now devoted to the 

 naming of new forms may be diverted to consider why we 

 wo have nomenclature at all, and whether it were not time 

 that we nuide use of these subspecific bricks to add something 

 to the existing structure of scientific ornithology. 



