the keel. As regards the struthious birds, they could not be likened to the duck, for in them at no age was there any indication of a single median centre of ossification, as Geoffroy had satisfied himself by his own observations made in Egypt many years before. Cuvier seems to have acquiesced in the corrections of his views made by Geoffroy, and attempted no rejoinder; but the attentive and impartial student of the discussion will see that a good deal was really wanting to make the latter's reply effective, though, as events have shown, the former was hasty in the conclusions at which he arrived, having trusted too much to the first appearance of centres of ossification, for, had his observations in regard to other birds been carried on with the same attention to detail as in regard to the fowl, he would certainly have reached some very different results.
In 1834 C. W. L. Gloger brought out at Breslau the first (and unfortunately the only) part of a Vollständiges Handbuch der Gloger. Naturgeschichte der Vögel Europa's, treating of the land-birds. In the Introduction to this book (p. xxxviii., note) he expressed his regret at not being able to use as fully as he could wish the excellent researches of Nitzsch which were then appearing (as has been above said) in the successive parts of Naumann's great work. Notwithstanding this, to Gloger seems to belong the credit of being the first author to avail himself in a book intended for practical ornithologists of the new light that had already been shed on Systematic Ornithology; and accordingly we have the second order of his arrangement, the Aves Passerinae, divided into two suborders: singing passerines (melodusae), and passerines without an apparatus of song-muscles (anomalae)—the latter including what some later writers called Picariae. For the rest his classification demands no particular remark; but that in a work of this kind he had the courage to recognize, for instance, such a fact as the essential difference between swallows and swifts lifts him considerably above the crowd of other ornithological writers of his time.
An improvement on the old method of classification by purely external characters was introduced to the Academy of Sciences of Sundevall. Stockholm by C. J. Sundevall in 1835, and was published the following year in its Handlingar (pp. 43-130). This was the foundation of a more extensive work of which, from the influence it still exerts, it will be necessary to treat later at some length, and there will be no need now to enter much into details respecting the earlier performance. It is sufficient here to remark that the author, even then a man of great erudition, must have been aware of the turn which taxonomy was taking; but, not being able to divest himself of the older notion that external characters were superior to those furnished by the study of internal structure, and that Comparative Anatomy, instead of being a part of zoology, was something distinct from it, he seems to have endeavoured to form a scheme which, while not running wholly counter to the teachings of Comparative Anatomists, should yet rest ostensibly on external characters. With this view he studied the latter most laboriously, and in some measure certainly not without success, for he brought into prominence several points that had hitherto escaped the notice of his predecessors. He also admitted among his characteristics a physiological consideration (apparently derived from Oken[1]) dividing the class Aves into two sections Altrices and Praecoces, according as the young were fed by their parents or, from the first, fed themselves. But at this time he was encumbered with the hazy doctrine of analogies, which, if it did not act to his detriment, was assuredly of no service to him. He prefixed an “Idea Systematis” to his “Expositio”; and the former, which appears to represent his real opinion, differs in arrangement very considerably from the latter. Like Gloger, Sundevall in his ideal system separated the true passerines from all other birds, calling them Volucres; but he took a step further, for he assigned to them the highest rank, wherein nearly every recent authority agrees with him; out of them, however, he chose the thrushes and warblers to stand first as his ideal “Centrum”—a selection which, though in the opinion of the present writer erroneous, is still largely followed.
The points at issue between Cuvier and Étienne Geoffroy St-Hilaire before mentioned naturally attracted the attention L'Herminier and Isidore Geoffroy St-Hilaire. of L'Herminier, who in 1836 presented to the French Academy the results of his researches into the mode of growth of that bone which in the adult bird he had already studied to such good purpose. Unfortunately the full account of his diligent investigations was never published. We can best judge of his labours from an abstract reprinted in the Comptes rendus (iii. pp. 12-20) and reprinted in the Annales des sciences naturelles (ser. 2, vol. vi. pp. 107-115), and from the report upon them by Isidore Geoffroy St-Hilaire, to whom with others they were referred. This report is contained in the Comptes rendus for the following year (iv. pp. 565-574), and is very critical in its character.
L'Herminier arrived at the conclusion that, so far from there being only two or three different modes by which the process of ossification in the sternum is carried out, the number of different modes is very considerable—almost each natural group of birds having its own. The principal theory which he hence conceived himself justified in propounding was that instead of five being (as had been stated) the maximum number of centres of ossification in the sternum, there are no fewer than nine entering into the composition of the perfect sternum of birds in general, though in every species some of these nine are wanting, whatever be the condition of development at the time of examination. These nine theoretical centres or “pieces” L'Herminier deemed to be disposed in three transverse series (rangées), namely the anterior or “prosternal,” the middle or “mesosternal” and the posterior or “metasternal”—each series consisting of three portions, one median piece and two side-pieces. At the same time he seems, according to the abstract of his memoir, to have made the somewhat contradictory assertion that sometimes there are more than three pieces in each series, and in certain groups of birds as many as six.[2] It would occupy more space than can here be allowed to give even the briefest abstract of the numerous observations which follow the statement of his theory and on which it professedly rests. They extend to more than a score of natural groups of birds, and nearly each of them presents some peculiar characters. Thus of the first series of pieces he says that when all exist they may be developed simultaneously, or that the two side-pieces may precede the median, or again that the median may precede the side-pieces—according to the group of birds, but that the second mode is much the commonest. The same variations are observable in the second or middle series, but its side-pieces are said to exist in all groups of birds without exception. As to the third or posterior series, when it is complete the three constituent pieces are developed almost simultaneously; but its median piece is said often to originate in two, which soon unite, especially when the side-pieces are wanting. By way of examples of L'Herminier's observations, what he says of the two groups that had been the subject of Cuvier's and the elder Geoffrey's contest may be mentioned. In the Gallinae the five well-known pieces or centres of ossification are said to consist of the two side-pieces of the second or middle series, and the three of the posterior. On two occasions, however, there was found in addition, what may be taken for a representation of the first series, a little “noyau” situated between the coracoids—forming the only instance of all three series being present in the same bird. As regards the ducks, L'Herminier agreed with Cuvier that there are commonly only two centres of ossification—the side-pieces of the middle series; but as these grow to meet one another a distinct median “noyau,” also of the same series, sometimes appears, which soon forms a connexion with each of them. In the ostrich and its allies no trace of this median centre of ossification ever occurs; but with these exceptions its existence is invariable in all other birds. Here the matter must be left; but it is undoubtedly a subject which demands further investigation, and naturally any future investigator of it should consult the abstract of L'Herminier's memoir and the criticisms upon it of the younger Geoffroy.
Hitherto our attention has been given wholly to Germany and France, for the chief ornithologists of Britain were occupying Macgillivray. themselves at this time in a very useless way—not but that there were several distinguished men who were paying due heed at this time to the internal structure of birds, and some excellent descriptive memoirs on special forms had appeared from their pens, to say nothing of more than one general treatise on ornithic anatomy.[3] Yet no one in Britain
- ↑ He says from Oken's Naturgeschichte für Schulen, published in 1821, but the division is to be found in that author's earlier Lehrbuch der Zoologie (ii. p. 371), which appeared in 1816.
- ↑ We shall perhaps be justified in assuming that this apparent inconsistency, and others which present themselves, would be explicable if the whole memoir with the necessary illustrations had been published.
- ↑ Sir Richard Owen's celebrated article “Aves,” in Todd's Cyclopaedia of Anatomy and Physiology (i. pp. 265-358), appeared in 1836, and, as giving a general view of the structure of birds, needs no praise here; but its object was not to establish a classification, or throw light especially on systematic arrangement. So far from that being the case, its distinguished author was content to adopt, as he tells us, the arrangement proposed by Kirby in the Seventh Bridgewater Treatise (ii. pp. 445-474), being that, it is true, of an estimable zoologist, but of one who had no special knowledge of ornithology. Indeed it is, as the latter says, that of Linnaeus, improved by Cuvier, with an additional modification of Illiger's—all these three authors having totally ignored any but external characters. Yet it was regarded “as being the one which facilitates the expression of the leading anatomical differences which obtain in the class of birds, and which therefore may be considered as the most natural.”
