Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/56

 46 11 N 1 T H L O G Y now relegate it to that Order. It is doubtless an extremely generalized form, 1 the survival of a very ancient type, whence several groups may have sprung ; and, whenever the secret it has to tell shall be revealed, a considerable step in the phylogeny of Birds can scarcely fail to follow. ^ Gralte. Allusion has also been made to the peculiarities of two other forms placed with the last among the Alectorides Eurypyga and Rhinoclietus being each the sole type of a separate Family. It seems that they might be brought with the Gruidx, Ps^hiidn, and Aramidx into a group or Suborder Grues, which, with the Fulicarix 3 of Nitzsch and Mr Sclater as another Suborder, would constitute an Order that may continue to bear the old Linnajan name G nil las. It must be borne in mind, however, that some members of both these Suborders exhibit many points of resemblance to certain other forms that it is at present necessary to place in different groups thus some Rallidx to the Gallinx, Grus to Otis, and so forth ; and it is as yet doubtful whether further investigation may not shew the resemblance to be one of affinity, and therefore of taxonomic value, instead of mere analogy, and therefore of no worth in that respect. We have next to deal with a group nearly as com- GaUinse. plicated. The true Gallinx are indeed as well marked a section as any to be found ; but round and near them cluster some forms very troublesome to allocate. The strange Hoactzin (Opisthocom/us) is one of these, and what seems to be in some degree its arrested development makes its posi tion almost unique, 4 but enough has already been said of it before (see vol. xii. p. 28, and supra p. 36). It must for the present at least stand alone, the sole occupant of a single Order. Then there are the Hemipodes or Button-Quails, which have been raised to equal rank by Prof. Huxley as Turnicomorphx ; but, though no doubt the osteological differences between them and the normal Gallinx, pointed out by him as well as by Prof. Parker, are great, they do not seem to be more essential than are found in different members of some other Orders, nor to offer an insuperable objection to their being classed under the designation Gallinx. If this be so there, will be no necessity for removing them from that Order, which may then be portioned into three Suborders 7/c mipodii standing some what apart, and Alectoropodes and Feristeropodes, which are more nearly allied the latter comprehending the Megapodiidx and Cracidx, and the former consisting of the normal Gallinx, of which it is difficult to justify the recognition of more than a single Family, though in that two types of structure are discernible. The Family of Sand-Grouse, Pteroclidx, is perhaps one of the most instructive in the whole range of Ornithology. In Prof. HUXLEY S words (Proceedings, 18G8, p. 303), they are &quot;completely intermediate between the Alectoromorphx [i.e., Gallinx] and the Peristeromorphx [the Pigeons]. They cannot be included within either of these groups without destroying its definition, while they are perfectly definable themselves.&quot; Hence he would make them an independent group of equal value with the other two. Almost the same result has been reached by Dr GADOW 1 Cariama is the oldest name for the genus, but being a word of &quot;barbarous &quot; origin it was set aside by Illiger and the purists in favour of Dicholophus, under which name it has been several times mentioned in the foregoing pages. 2 A brief description of the egg and young of Cariama crtstata pro duced in the Jurdin des Plantes at Paris is given in the Zoological Society s Proceedings for 1881, p. 2. 3 This group would contain three families RallidiE, Ileliornithidie (the Finfoots of Africa and South America), and the Mesitidse of Madagascar whose at least approximate place has been at last found fr them by M. A. Milne-Edwards (Ann. Sc. Nuturclles, ser. 6. vii. No. 6). very similar. clidie. (&amp;lt;&amp;gt;p. cit., 1882, pp. 331, 332). No doubt there are strong and tempting reasons for taking this step ; but peradven- ture the real lesson taught by this aggregation of common characters is rather the retention of the union of the Gallinx and Columbx into a single group, after the fashion of by-gone years, under the name, however meaningless, of Rasores. Failing that, the general resemblance of most parts of the osteology of the Sand-Grouse to that of the Pigeons, so well shewn by M. Milne-Edwards, combined with their Pigeon-like pterylosis, inclines the present writer to group them as a Suborder of Columbse, ; but the many Columke, important points in which they differ from the more normal Pigeons, especially in the matter of their young being clothed with down, and their coloured and speckled eggs, 5 must be freely admitted. Young Sand Grouse are described as being not only &quot;Dasypaides&quot; but even &quot; Pnecoces &quot; at birth, while of course every one knows the helpless condition of &quot;Pipers&quot; that is, Pigeons newly-hatched from their white eggs. Thus the opposite condition of the young of these two admittedly very near groups inflicts a severe blow on the so-called &quot; physiological ; method of dividing Birds before mentioned, and renders the Pterodidx so instructive a form. The Columbx, considered in the wide sense just suggested, would seem to have possessed another and degenerate Suborder in the Dodo and its kindred, though the extirpation of those strange and monstrous forms will most likely leave their precise relations a matter of some doubt ; while the third and last Suborder, the true Columbx, is much more homogeneous, and can hardly be said to contain more than two Families, Columbidx and Didunculidx the latter consisting of a single species peculiar to the Samoa Islands, and having no direct con nexion with the Dididx or Dodos, though possibly it may bo found that the Papuan genus Otidiphups presents a form linking it with the Columbidx. The Gallinx would seem to hold a somewhat central Groups position among existing members of the Carinate division, 7 allied to whence many groups diverge, and one of them, the Opis- tkocomi or ffeteromorphx of Prof. Huxley, indicates, as he has hinted, the existence of an old line of descent, now almost obliterated, in the direction of the Musophagidx, and thence, we may not unreasonably infer, to the Coccygomorphx of the same authority. But these &quot; Coccygomorphs &quot; would also appear to reach a higher rank than some other groups that we have to notice, and therefore, leaving the former, we must attempt to trace the fortunes of a more remote and less exalted line. It has already been stated that the Gavix are a group closely allied to though somewhat higher than the Limicolx, and that at least two forms of what have here been called Grallx present an affinity to the latter. One of them, Rhinochttus, has been several times thought to be con nected through its presumed relative Eurypyga (from which, however, it is a good way removed both as regards distribution and structure) with the Heriodiones, Herons. On the other hand the Gavix would seem to be in like manner related through Phaethon (the TROPIC-BIRD, f/.v.} with the Steganopodes or Dysporomorpksd of Prof. Huxley, among which it is usually placed, though according to Prof. MIVART (Trans. Zool. Society, x. pp. 364, 36&quot;)) wrongly. These supposed affinities lead us to two other groups of Birds that have, it has been proved, some com mon characters ; and from one or the other (no one yet can say which) the Accipitres would seem to branch off 5 This fact tells in favour of the views of Dr Gadow and those who hold the Sand-Grouse to be allied to the Plovers ; but then he places the Pigeons between these groups, and their eggs tell as strongly the other way. 6 Cf. Phil. Transactions, 1867, p. 349. 7 Cf. Prof. Parker s remarks in the Philosophical Transactions for 1809, p. 7S5.
 * Mesites, just mentioned, presents a case which may, however, be