HE following comments were originally prepared as a communication at the Twentieth Congress of the A. O.U. They are presented here at the re- quest of the editor of TI CoroR, but have been somewhat modified in the interests of brevity and clearness. Nomenclature is not a subject of much popular interest, but since the varied faunal conditions of California bring it constantly to the attention of the system- atic zoologists of the State, the present publication may be warranted. 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. Merrian, 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 imlossible, 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 oœ 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 ttough 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 nanes? The foregoing cases are those in which actzal 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. In the quail also Mr. Nelson has shown intergradation between a whole chain of contiguous races reaching from the eastern United States to southern Mexico and therefore we must link t9gether in a trinomial name our white-throated, bar- breasted, bobwhite (Colbzus virgizœazus)with a chestnut-bellied, black-throated, bird bearing no resemblance to it except in generic characters. And ye t a race separated by some miles of country and not showing any actual intergradation with its nearest geographic ally, will be designated as a species with a binomial name, even though it be much more closely related to either of the above extremes than they are to each other ! This practice to my mind loses sight.of the primary object of nomenclature which I take to be the designation of a distinguishable form in nature by a name which, when we see or hear it, will recall that form to mind. Anyone seeing a trinomial name today has no idea whether the form de- noted is a slight variation of the stock indicated by the specific name or something totally different perhaps occupying a region hundreds of miles distant, the inter- vening country being occupied by other forms between which by mere chance the thread of evolutionary development is not yet quite severed. The result of this use of trinomials will tend to the complete abandonment of this useful form of name. In fact some writers on mammals have already practic- ally lapsed into a pure binomial nomenclature. It seems to me that this tendency is very much to be regretted. A trinomial properly used means just twice as much as a binomial, and with the present practice of naming every slightly differ- entiated form, a purely binomial system will soon mean nothing except to the specialist on each group--the mind cannot place such a host of names. The tri- nomial on the other hand properly used gives at once, in the specific names, a due to the general character of the form referred to. By continuing the practice of naming island and isolated forms by the degree qfdifference principle as is now done in the A. O. U. Checklist, and by extending this practice to the breaking up of such widely divergent series as the song spar- rows and quail (which are comparatively few), I think that the valuable system of trimonials can be preserved. That the series just referred to must be broken arbitrarily, I admit, and that they catz be broken arbitrarily by such a body as the A. O. U. Committee and still meet with general atisfaetion there is, I think, no doubt. Genera have been so divided in numerous instances and the conditions prevailing in both eases are the same, i.e., current personal opinion. The segregation of geographic races and the tracing of evolutionary develop- ment constitute one of the most valuable aud instructive phases of modern system- atic work, but weshould realize that all the facts so discovered cannot be em- bodied in our nomenclature and that if we give up the effort to so embody them, we in no sense mean to belittle them. To my mind we should aim to keep a name as nearly as possible to its original province and to remember that "nomenclature is a means not an end of zoological science."