ORNITHOLOCi Y 



4:; 



pithy — "Birds are only glorified Reptiles." It is not 

 intended here to enter upon their points of resemblance 

 and differences. These may be found summarized with 

 more or less accuracy in any text-book of zoology. We 



shall content ourselves by remarking that by the naturalist 

 just named Birds and Reptiles have been brigaded together 

 under the name of Sauropsida as forming one of the three 

 primary divisions of the Vertebrata — the other two being 

 Ichthyopsida and Mammalia. Vet Birds have a right to 

 be considered a Class, and as a Class they have become so 

 wholly differentiated from every other group of the Animal 

 Kingdom that, among recent and even the few fossil forms 

 known to us, there is not one about the assignation of 

 whieh any doubt ought now to exist, though it is right to 

 state that some naturalists have even lately refused a place 

 among Aves to the singular Archeeopteryx, of whieh the 

 remains of two individuals — most probably belonging to 

 as many distinct forms 1 — have been discovered in the 

 quarries of Solenhofen in Bavaria. Yet one of them has 

 been referred, without much hesitation, by Prof. Vogt to 

 the Class Reptilia on grounds which seem to be mistaken, 

 since it was evidently in great part if not entirely clothed 

 with feathers. 3 The peculiar structure of Archeeopteryx 

 has already been briefly mentioned and partly figured in 

 this work (Birds, vol. iii. p. 728-9), and, while the present 

 writer cannot doubt that its Bird-like characters predomin- 

 ate over those which are obviously Reptilian, he will not 

 venture to declare more concerning its relations to other 

 Birds, and accordingly thinks it advisable to leave the 

 genus as the sole representative as yet known of the Sub- 

 class Sawrurae, 3 established for its reception by Prof. 

 Hackel, trusting that time may shew whether this pro- 

 visional arrangement will be substantiated. The great use 

 of the discovery of Archasopteryx to naturalists in general 

 is well known to have been the convincing testimony it 

 afforded as to what is well called " the imperfection of the 

 Geological Record." To ornithologists in particular its 

 chief attraction is the evidence it furnishes in proof of the 

 evolution of Birds from Reptiles; though, as to the group 

 of the latter from which the former may have sprung, it. 

 tells us little that is not negative. It throws, for instance, 

 the Pterodactyls — so often imagined to be nearly related to 

 Birds, if not to be their direct ancestors — completely out 

 of the line of descent. Next to this its principal advan- 

 tage is to reveal the existence at so early an epoch of Birds 

 with some portions of their structure as highly organized 

 as the highest of the present day, a fact witnessed by its 

 foot, whieh, so far as can be judged by its petrified relics, 



1 See Prof. Seeley's remarks on the differences between the two 

 specimens, in the Geological Magazine for October 1SS1. 



- Prof. Vogt lays much stress m the absence of feathers from certain 

 parts of the body of the second example of Archeeopteryx now, thanks 

 to Dr Werner Siemens, in the museum of Berlin. But Prof. Vogt 

 himself shews that the parts of the body devoid of feathers are also 

 devoid of skin. Now it is well known that amongst most existing 

 Birds the ordinary "contour-feathers" have their origin no dei pel 

 than the skin, and thus if that decayed and were washed away the 

 feathers growing upon it would equally be lost. This has evidently 

 happened (to judge from photographs) to the Berlin specimen just 

 as to that which is in London. In each case, as Sir R. Owen most 

 rightly suggested of the latter, the remains exactly call to mind the 

 very familiar relics of Birds found on a seashore, exposed perhaps for 

 weeks or even months to the wash of the tides so as to lose all but the 

 deeply-seated feathers, and finally to be embedded in tin- si.lt soil. 

 I'n. I. Vogt's paper is in the Revue Stientifique, ser. 2, ix. p. '241, and 

 an English translation of it in The Ibis for 1880, p. 434. 



3 Prof. Hackel seems first to have spelt this word Sauriurse, in 

 which form it appears in his Allgemcinr Entwickfii<»r/,Ml,nlt/r ,h r 

 Organismen, forming the second volume of his Genei-eli? Mitrpholngic 

 (pp. xi. and exxxix.), published at Berlin in 1866, though on plate 

 vii. of the same volume it appears as Saurvuri. Whether the masculine 

 or feminine termination be preferred matters little, though the latter 

 i come into general use, but the interpolation of the i in the middle of 

 the word appears to be against all the laws of orthography. 



might well be that of a modern Crow. The fossil remains 

 of many other Birds, for example Prof. Seeley's Enaliornis 

 (Quart. Journ. <;,■•!. Society, 1876, pp. 496-512), Sir P. 

 Owen's Odontopteryx (Birds, vol. iii. p. 729), Gastornis, 

 Prof. Cope's Diatryma (Proc. Acad. X. Sc. Philadelphia, 



April 1876), and some i -e, are ton fragmentary to serve 



the purposes of the systematist; but the grand discoveries 

 of Prof. .Marsh, spoken of above, afford plentiful hints as 

 to the taxonomy of the Class, and their bearing deserves 

 the closest consideration. First of all we find that, while Antiquity 

 Birds still possess the teeth they had inherited from their ' ' the 

 Reptilian ancestors, two remarkable and very distinct types ''''!' 

 of the Class had already made their appearance, and we Marinate 

 must note that these two types are those which persist at types, 

 the present day, and even now divide the Class into 

 Ratitx and Carinatse, the groups whose essentially distinct 

 characters were recognized by Merrem. Furthermore, 

 while the Ratite type (Hesperornis) presents the kind of 

 teeth, arrayed in grooves, which indicate (in Reptiles ;it 

 least) a low morphological rank, the Carinate type (Ich- 

 thyornis) is furnished with teeth set in sockets, and shew- 

 ing a higher development. On the other hand this early 

 Carinate type has vertebras whose comparatively simple, 

 biconcave form is equally evidence of a rank unquestion- 

 ably low; but the saddle-shaped vertebrae of the con 

 temporary Ratite type as surely testify to a more exalted 

 position. Reference has been already made to this com- 

 plicated if not contradictory state of things, the true 

 explanation of which seems to be out of reach at present. 

 It has been for some time a question whether the Patite 

 is a degraded type descended from the Carinate, or the 

 Carinate a superior development of the Ratite type. 

 Several eminent zoologists have declared themselves in 

 favour of the former probability, and at first sight most 

 people would be inclined to decide with them ; for, on this 

 hyp ithesis, the easiest answer to the question would be 

 found. But the easiest answer is not always the true one ; 

 and to the present writer it seems that before this question 

 be answered, a'reply should be given to another —Was the 

 first animal which anyone could properly call a " Bird," as 

 distinguished from a "Reptile," possessed of a keeled 

 sternum or not 1 ! Now Birds would seem to have been 

 differentiated from Reptiles while the latter hail biconcave 

 vertebras, and teeth whose mode of attachment to the jaw 

 was still variable. There is no reason to think that at 

 that period any Reptile (with the exception of Pterodactyls, 

 whieh, as has already been said, are certainly not in the 

 line of Birds' ancestors) had a keeled sternum. Hence it 

 seems almost impossible that, the first. Bird should have 

 possessed one ; that is to say, it must have been practically 

 of the Ratite type. Prof. Marsh has shewn that there is 

 good reason for believing that the power of flight was 

 gradually acquired by Birds, and with that power would 

 be associated the development of a keel to the sternum, on 

 which the volant faculty so much depends, and with 

 which it is so intimately correlated that in certain forms 

 which have to a greater or less extent given up the us. of 

 their fore-limbs the keel though present has become pro- 

 portionally aborted. Thus the Carinate type would, from 

 all we can see at present, appear to have been evolved 

 from the Patite. This view receives further support from 

 a consideration of the results of such embryological research 

 as has already been made — the unquestionable ossification 

 of the Ratite sternum from a smaller number of paired 

 centres than the Carinate sternum, in whieh (with the 

 doubtful exception of the Anatidai) an additional, unpaired 

 centre makes its appearance. Again the geographical dis- 

 tribution of existing, or comparatively recent, Ratite forms 

 points to the same conclusion. That these forms — Moa, 

 Kiwi, Emeu and Cassowary, Rhea, and finally Ostrich — ■ 



