Page:EB1911 - Volume 20.djvu/351

TAXONOMY] character of this kind is not to be despised as a practical mode of separating the birds which possess it; and, more than this, it would appear that the discovery thus announced was the immediate means of leading to a series of investigations of a much more important and lasting nature—those of Johannes Müller to be presently mentioned.

Again we must recur to that indefatigable and most original investigator Nitzsch, who, having never intermitted his study of the particular subject of his first contribution to science, long ago noticed, in 1833 brought out at Halle, where he was professor of Zoology, an essay with the title Pterylographiae Avium Pars prior. It seems that this was

issued as much with the object of inviting assistance from others in view of future labours, since the materials at his disposal were comparatively scanty, as with that of making known the results to which his researches had already led him. Indeed, he only communicated copies of this essay to a few friends, and examples of it are comparatively scarce. Moreover, he stated subsequently that he thereby hoped to excite other naturalists to share with him the investigations he was making on a subject which had hitherto escaped notice or had been wholly neglected, since he considered that he had proved the disposition of the feathered tracts in the plumage of birds to be the means of furnishing characters for the discrimination of the various natural groups as significant and important as they were new and unexpected. There was no need for us here to quote this essay in its chronological place, since it dealt only with the generalities of the subject, and did not enter upon any systematic details. These the author reserved for a second treatise which he was destined never to complete. He kept on diligently collecting materials, and as he did so was constrained to modify some of the statements he had published. He consequently fell into a state of doubt, and before he could make up his mind on some questions which he deemed important he was overtaken by death. Then his papers were handed over

to his friend and successor Professor Burmeister, now and for many years past of Buenos Aires, who, with much skill, elaborated from them the excellent work known as Nitzsch’s Pterylographie, which was published at Halle in 1840, and translated into English for the Ray Society in 1867. There can be no doubt that Professor Burmeister discharged his editorial duty with the most conscientious scrupulosity; but, from what has been just said, it is certain that there were important points on which Nitzsch was as yet undecided—some of them perhaps of which no trace appeared in his manuscripts, and therefore as in every case of works posthumously published, unless (as rarely happens) they have received their author’s “imprimatur,” they cannot be implicitly trusted as the expression of his final views. It would consequently be unsafe to ascribe positively all that appears in this volume to the result of Nitzsch’s mature consideration. Moreover, as Professor Burmeister states in his preface, Nitzsch by no means regarded the natural sequence of groups as the highest problem of the systematist, but rather their correct limitation. Again, the arrangement followed in the Pterylographie was of course based on pterylographical considerations, and we have its author’s own word for it that he was persuaded that the limitation of natural groups could only be attained by the most assiduous research into the species of which they are composed from every point of view. The combination of these three facts will of itself explain some defects, or even retrogressions, observable in Nitzsch’s later systematic work when compared with that which he had formerly done. On the other hand, some manifest improvements are introduced, and the abundance of details into which he enters in his Pterylographie render it far more instructive and valuable than the older performance. As an abstract of that has already been given, it may be sufficient here to point out the chief changes made in his newer arrangement. To begin with,

the three great sections of aerial, terrestrial, and aquatic birds are abolished. The “Accipitres” are divided into two groups, Diurnal and Nocturnal; but the first of these divisions is separated into three sections: (1) the Vultures of the New World, (2) those of the Old World, and (3) the genus Falco of Linnaeus. The “Passerinae,” that is to say, the true Passeres, are split into eight families, not wholly with judgment but of their taxonomy more is to be said presently. Then a new order “Picariae” is instituted for the reception of the Macrochires, Cuculinae, Picinae, Psittacinae and Amphibolae of his old arrangement, to which are added three others—Caprimulginae, Todidae and Lipoglossae—the last consisting of the genera Buceros, Upupa and Alcedo. The association of Alcedo with the other two is no doubt a misplacement, but the alliance of Buceros to Upupa, already suggested by Gould and Blyth in 1838 (Mag. Nat. History, ser. 2, ii. pp. 422 and 589), though apparently unnatural, has been corroborated by many later systematisers; and taken as a whole the establishment of the Picariae was certainly a commendable proceeding. For the rest there is only one considerable change, and that forms the greatest blot on the whole scheme. Instead of recognizing, as before, a subclass in the Ratitae of Merrem, Nitzsch now reduced them to the rank of an order under the name “Platysternae,” placing them between the “Gallinaceae” and “Grallae,” though admitting that in their pterylosis they differ from all other birds, in ways that he is at great pains to describe, in each of the four genera examined by him—Struthio, Rhea, Dromaeus and Casuarius. It is significant that notwithstanding this he did not figure the pterylosis of any one of them, and the thought suggests itself that, though his editor assures us he had convinced himself that the group must be here shoved in (eingeschoben is the word used), the intrusion is rather due to the necessity which Nitzsch, in common with most men of his time (the Quinarians excepted), felt for deploying the whole series of birds into line, in which case the proceeding may be defensible on the score of convenience. The extraordinary merits of this book, and the admirable fidelity to his principles which Professor Burmeister showed in the difficult task of editing it, were unfortunately overlooked for many years, and perhaps are not sufficiently recognised now. Even in Germany, the author’s own country, there were few to notice seriously what is certainly one of the most remarkable works ever published on the science, much less to pursue the investigations that had been so laboriously begun. Andreas Wagner, in his report on the progress of