^°''i9lV"] ^^'•^^^ Literature. 233 



three forms here distinguished, I am reluctantly following recent prece- 

 dent. . . .1 have no evidence whatever that the three forms, ater, artemisice, 

 and obscurus, intergrade continuously and geographically between each 

 other. In other words their distinctness is specific on any criterion ex- 

 cepting those of relatively close similarity in gross appearance, and individ- 

 ual overlapping in separate characters." He appears to forget, for the 

 time being, that while the Gowbird group has a continuous, though over 

 some unfavorable areas a sparse, distribution over the greater part of the 

 North American continent, his "lack of evidence" is purely negative 

 evidence; and that forty to fifty years ago scores, indeed hundreds, of 

 vertebrate forms were ranked as unquestionable species which have since 

 been found to intergrade as additional material came to light from inter- 

 vening localities, and their subspecific status and complete intergradation 

 with other forms demonstrated. When it comes to naming such slightly 

 differentiated forms as these Cowbirds, surely the probabilities in the case, 

 as established by experience, should receive some consideration, and be 

 allowed at least as much weight as the absence of contrary evidence. 



We are even more surprised that Mr. Grinnell should advocate abandon- 

 ing the use of trinomials, on account of the " tendency among ornithologists 

 nowadays to 'reduce' all congeneric forms in plastic groups to subspecific 

 status." It may be admitted that here and there may be found an orni- 

 thologist who is given to excessive 'lumping,' but in general the attitude is 

 reasonably conservative, and the excessive lumpers are not the standard 

 bearers. Yet Mr. Grinnell takes the matter very seriously, continuing: 

 "Indeed it might even be urged with reason that trinomials have outlived 

 their usefulness, and that a pure binomial system, as consistently followed 

 by Sharpe in his 'Handlist of Birds,' is adequate and decidedly less cmn- 

 bersome." On this point we have already expressed ourselves with some 

 emphasis in two reviews of this same 'Handlist,' ' the gist of which is that 

 such uniform treatment of all forms, whether known to intergrade or not, 

 is grossly misleading, giving no clue to their real or 'genetic' relationships 

 or to their relative distinctness and degree of differentiation. Sharpe, for 

 instance, who is here cited as the model after whom we should pattern, 

 recognizes hosts of forms as full species that really have no claim whatever 

 to recognition in nomenclature, including forms that have even been aban- 

 doned by their proposers, and others condemned by the consensus of 

 experts. If he had in each case, by the use of trinomials, given them the 

 value currently assigned them, even the unwary layman would have some 

 proper conception of their value and relationships, but now all have to 

 him the same value and only the expert can make the proper discrimi- 

 nation under this uniform and "consistent" binomial method. 



Mr. Grinnell has also described two new forms of the Bewick Wren group ^ 



1 Auk, XXVII, Jan. 1910, pp. 93-95 (c/. p. 95); Science, N. S., XXXI, pp. 265- 

 267, February 18, 1910. 



2 Two heretofore unnamed Wrens of the Genus Thryomanes. By Joseph Grinnell. 

 University of California Publ., Zoology, Vol. V, No. 8, pp. 307-309. February 21, 

 1910. 



