On Okapia, a new Genus of Giraffidæ, from Central Africa .
1902; Wiley; Volume: 16; Issue: 6 Linguagem: Catalão
10.1111/j.1096-3642.1902.tb00032.x
ISSN0084-5620
Autores Tópico(s)Lepidoptera: Biology and Taxonomy
ResumoThe Transactions of the Zoological Society of LondonVolume 16, Issue 6 p. 279-314 Free Access On Okapia, a new Genus of Giraffidæ, from Central Africa. E. RAY LANKESTER M.A., LL.D., F.R.S., F.Z.S., E. RAY LANKESTER M.A., LL.D., F.R.S., F.Z.S. Director of the Natural History Departments of the British Museum, Correspondent of the Institute of FranceSearch for more papers by this author E. RAY LANKESTER M.A., LL.D., F.R.S., F.Z.S., E. RAY LANKESTER M.A., LL.D., F.R.S., F.Z.S. Director of the Natural History Departments of the British Museum, Correspondent of the Institute of FranceSearch for more papers by this author First published: August 1902 https://doi.org/10.1111/j.1096-3642.1902.tb00032.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References 1 See also the 'Times,' May 7th, 1901. 2 May 27th, 1902. – Now shown not to be hornless; see Appendix, p. 304. 1 The Okapi is not unfrequently captured in dug-out traps and speared by the natives in the neighbourhood of the Independent Congo State fort whence Sir Harry Johnston obtained it. It is not an animal which can attract the sportsman, on account of the heat and darkness of the forest where it lives; but I have no doubt that anyone who would go and stay six months or more on this spot would be able to obtain several complete specimens without firing a shot. 1 See Appendix and text-figure on p. 304, giving an account of two new specimens, male and female, with horns two to three inches in length. 1 The very much smaller relative size of the front teeth of the lower jaw of Okapia than of Giraffa is shown by a comparison of the drawings given here, viz. text-figure 12, p. 293, showing the milk-dentition of this region in Giraffa, with the permanent dentition of Okapia (Pl. XXXII. fig. 12), and the text-figure 9, showing the permanent and the deciduous canines of Giraffa, compared with the permanent canines of Okapia, of Samotherium, and of Sivatherium, drawn of natural size. 1 See A. Brandt, "Ueber Hörner und Geweihe," Festschrift Leuckarts, 1892. Recently Dr. J. Ulrich Dürst has published a valuable essay, entitled, "Versuch einer Entwickelungsgeschichte der Hörner der Cavicornia," in the Festschrift zur Feier des 70. Geburtstages von Prof. Dr. Ad. Kræmar (Frauenfeld, 1902), for the opportunity of seeing which I am indebted to Dr. Forsyth Major. Among the more important points established by Dürst is the fact that the separated rudiment of the horn-core which appears in young Bovidæ is not cartilage (as sometimes asserted), but, as one would have supposed, osteogenetic tissue. 7 It seems that we still do not possess a really thorough histological and embryological study of the ossicusp or bone of the horn and antler of Pecora. 8 I venture (as modifying somewhat what I have said in the body of this memoir) to put forward the hypothesis that whilst the primitive element of the ossicusp is an outgrowth of the outer table of a cranial bone, a secondary accessory bony element has been developed upon and in connection with this which has a characteristic histological structure, and is referable to the same class of bony growths as those produced pathologically in cases of rheumatic arthritis. This secondary element of the bony core of the Pecorine horn is seen in a comparatively unmodified condition as the hollow cone-like caps or epiphyses of the horn-cores of Giraffa. I suggest as probable that the caducous portion of the Cervine antler is genetically identical with this epiphysial cap, whilst the base or "Rosenstock" of the Cervine antler is identical with the more or less protuberant boss or tumescence which is a direct outgrowth of the outer tabula of a cranial bone in Giraffidæ. In vertical sections now before me of the bony horns of full-grown Giraffes, it is evident that this basal (and more primitive) element of the ossicusp is of considerable volume, and actually rises up some four or five inches, so as to form the base and axis of the parietal horns, the epiphysial cap having the form of a hollow cone which rests on and is fused with this deeper cone-like upgrowth. I find myself in agreement with Dr. Dürst, who recognizes the existence of this truly frontal upgrowth in Cavicornia as "Hornstiel," and identifies it "in gewisser Hinsicht" with the "Rosenstock" of Cervidæ. 9 The "Hornstiel," or horn-pedicle, or horn-boss, though small, is present in varying degree, according to Dr. Dürst, in all Cavicornia. On the other hand, the "Hornzapf," or horn-cone, of the Cavicornia (as distinguished from the horn-boss) originates as a mass of osteogenetic tissue, separate from that which forms the frontal bone; it constitutes by far the greater bulk of the bony structure of the horn. It seems to me probable that the Cavicorn's bony horn-cone is identical with the hollow conical bony epiphysis or cap of the Giraffe's horn, and, consequently, with the deciduous element of the Cervine antler. In Cavicornia the primitive bony element of the horn, viz. the horn-boss, or Hornstiel, has been further reduced than it is in the Giraffe, and its place is actually taken by the secondary accessory structure–the horn-cone or epiphysial cap. A secondary growth, originally developed as an accessory to a primitive organ, has here (as happens in other instances) acquired overwhelming vigour, and been substituted for the primitive organ, which consequently dwindles and nearly disappears. The Giraffes, with their well-developed cranial horn-bosses and relatively small epiphysial horn-caps (Hornzapffen) are intermediate between the Cavicorns and a primitive group which had no epiphysial horn-caps, but only horn-bosses (Hornstiele). Our immature Okapia is actually in the latter condition, and it seems (so far as adult specimens can allow one to judge) that the horn-cores of the long-extinct Dinocerata also were true horn-bosses of the cranial bones and not epiphysial–that is to say, not "Hornzapffen," or horn-caps.–E. R. L., April 30th, 1902. The actual mode of growth of the frontal "ossicusps" three inches in length, revealed in the adult Okapi recently received in Brussels, has yet to be ascertained.–May 23rd, 1902. 1 The existence of such a rudiment was at first supposed by me to exist, and a notice by me in an illustrated weekly paper is quoted by Dr. Dürst (loc. cit.) to that effect. I found, however, on cutting open the skin of the head after it had been received from the taxidermist that there were no thickenings of the integument over the frontal bosses, but that the taxidermist had taken the liberty of inserting a small plug of cotton-wool over each frontal boss, so as to give a strongly marked prominence to the integument in this position.–E. R. L., April 30th, 1902. It now appears (May 23rd) that my original supposition was probably correct, since the Brussels skull of an adult Okapi shows ossicusps three inches in length, though their mode of growth is not yet ascertained. 1 May 27th, 1902.–So as to take cognizance of the fact as to the existence of bony frontal horns in the adult, revealed by the specimen received in Brussels a month ago. See Appendix, p. 304. Citing Literature Volume16, Issue6August 1902Pages 279-314 This article also appears in:Hidden Gems ReferencesRelatedInformation
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