725 
19 21 •] and their part in Evolution . 
by no means unknown ; or again, chequering, a character 
common to some domestic Pigeons but probably unknown 
in the pure wild Rock-Pigeon, is found in a few wild species 
of Pigeon— e.g. the Guinea Pigeon of Africa, and so on. 
I am quite in agreement with Colonel Meinertzhagen that 
a mutation cannot establish a subspecies, since to my mind a 
subspecies is entirely an environmental or geographic form ; 
and if my reasoning in the earlier part of this paper be 
correct, a geographic form could never become a separate 
species. It might, I conceive, be possible for some factor to 
become “ latent ” or lost through a change in the environ¬ 
ment, and then a new species would evolve. Such 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 omitting dimorphic 
forms which possibly fall in the above category, have we 
any definite knowledge of a new species originating as a 
mutation ? Omitting Pavo nigripennis , which has not, I 
believe, occurred in a wild state, I can only recall the Italian 
Little Owl, Athene chiaradice (Giglioli, Ibis, 1903, 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 problem 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 pour destructive criticism on the observations and 
thoughts of the previous writers ; but they have 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 
we have nomenclature at all, and whether it were not time 
that we made use of these subspecific bricks to add something 
to the existing structure of scientific ornithology. 
