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44 THE CONDOR { VoL. V The writer is speaking solely for himself, and no matter whether his views be ultimately endorsed or condemned by the A. O. U. Committee, he wishes to be understood as always advocating adherence to the Code and Check-llst of the A. O. U. as'the only way to secure nniformity--the main object for which we strive. He is also well aware much the same problems as here presented have already been discussed by Dr. Merria?n, Dr. Allen and others, so that no originality is claimed,'but merely an expression of opinion. The use of trinomials, as established by the A. O. U. Code and adopted by most writers on vertebrates, is generally understoqd to be the designation of the geographic variants of a wide ranging form, which merge into one another where their ranges join--i. e., indpient species, produced by peculiar environments, but which are not yet entirely isolated from one another. The forms so designated are called subspecies. As a convenient method of deciding whether a certain race or form should be regarded as a species or subspecies, actual intergradation between contiguous forms was adopted by the A. O. U. Code as the criterion. When we come to name resident birds of coastwise islands which are but slightly differentiated from the mainland stock we at once confront a problem. Intergradation in the sense of interbreeding is iml?ossible, consequently some writers maintain that all island forms must be regarded as species (binomial). But intergradation in the sense of overlapping of characters exists in many cases, and on this ground others term them subspecies (trinomial) and in practice a form is judged to be a species or subspecies by the degree o difference exhibited between it and its nearest geographic relfitive. This latter would seem to be the more log- ical course, since by the former plan we might just as well separate the song spar- rows for instance of San Clemente and San Miguel Islands since they are geo- graphically separated into two races, though as yet we cannot detect any tangible difference between them! Extending the practice of recognizing overlapping of characters as intergrada- tion, we find the geographically isolated tt?ough closely allied Florida burrowing owl listed as a subspecies of the bird of the plains, and other similar cases culmin- ating with Mr. Nelson's recently described "subspecies" of the Cuban cliff swal- low from western Mexico! This practice is severely criticised by some, but if we regard these forms as species solely on account of geographic isolation, what are we going to do with the martin of Southern Mexico which Mr. Nelson states is in- distinguishable from the Cuban martin. Surely we cannot separate it purely on geographic grounds and if we do not separate it we are calling by the same name two forms which have probably developed independently, and tbus loosing sight in ottr nomenclatztre of a fact of evolution, the indication ot which facts is, accord- ing to the strict adherents of the actual intergradation principle, the main object of trinomial nomenclature. The question naturally occurs can we indicate in our nomenclature all these facts of evolution without seriously impairing the utility of our names as na?nes? The foregoing cases are those in which actz?al intergradation is either impossi- ble or doubtful. Let us now consider some where it is admittedly a fact. Mr. Ridgway has shown that all of our cohtinental song sparrows pass im- perceptibly one into the other where their ranges touch, and as a result we have the little speckled-breasted bird of the California salt-marshes listed as a subspecies of the big gray bird of Alaska, more than twice its size, and which any novice would regard as a perfectly distinct kind of bird.