720 
Mr. J. Lewis Bonhote : Subspecies 
[Ibis, 
XXXVII .—Subspecies and their part in Evolution. 
By J. Lewis Bonhote, M.A., M.B.O.U. 
Mr. Loomis's' letter in ‘The Ibis’ (1920, p. 964) on sub¬ 
species contains many grains of sound commonsense, which, 
if it only makes us pause for a few moments to consider 
what subspecies really are, how they arise, and whither their 
recognition is leading us, will have had a most beneficial 
effect. It must be remembered—and the fact is too often 
forgotten—that nomenclature is a means to an end, and not 
the end itself. In order to be able to handle the vast array 
of facts presented by a study of Nature, naturalists have 
invented a system whereby relationships between various 
groups are roughly shown by methods of grouping and 
naming; and up to some 20 years ago the “ species ” was the 
smallest “ item ” in that system. The object of this system, 
however, was not merely to enable us to arrange our collec¬ 
tions in cabinets, but that, having arranged them in some 
sort of a natural order, we might attempt with greater ease 
to unravel some of the mysteries of Nature’s laws. I am 
not prepared to say that such a “ unit” as a species actually 
exists in Nature. When it does it must have been brought 
about either because that species arose as a discontinuous 
variation, or because the connecting series of small varia¬ 
tions have been lost so as to leave it without any obviously 
near relatives. This latter is the case, as we know, with 
many present-day species, and thus is formed what Mr. 
Loomis calls a “ fundamental bird unit,” although I do not 
agree with him that they are in any way “fundamental”; 
nevertheless, for practical purposes, they may be considered 
as “ units.” 
Of late years the accumulating of larger and more care¬ 
fully collected series has shown us that many of what were 
previously considered merely as sporadic varieties are in 
reality definite phases common to all individuals of a par¬ 
ticular species in a certain area; and that such a form 
intergrades gradually into the form which happens to be 
next it geographically. These came to be recognized as 
