The myology of the upper and lower extremities of Orycteropus capensis / by John Charles Galton.

  • Galton, John Charles, 1840-
Date:
[1868]
Catalogue details

Licence: Public Domain Mark

Credit: The myology of the upper and lower extremities of Orycteropus capensis / by John Charles Galton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    posterior angle of eyelid to anterior border of concha of ear, 4 inches; from anterior border of concha to tip of ear, 7 inches; from posterior border of calcaneum to tip of nail of middle toe (plantar surface), 10^ inches; from anterior border of radius, or pos- terior border of wrist, to extremity of longest digit (dorsal measurement), 7f inches. The “manns” in this animal has only four digits, the pollex being rudimentary. The homologue of the “ middle ” digit is the longest, the index being shorter, but of very nearly equal length. This character serves to distinguish O. Capensis from the only other species, JEtliiopicm^. The homologue of the “ fourth” finger comes next in size, the little finger being by far the shortest. The “pes ” has a large oval callosity in the centre of the sole. The heel is extremely well marked, and is, moreover, covered on its plantar aspect with a callous pad. This character, taken together with the plantar callosity, indicates obviously a plantigrade mode of progression. Such a conclusion is supported by Daniell’s figures, to which refer- ence has already been made Pive digits are present, of which the middle is the longest, the second being shorter, but very nearly of the same length. The hallux comes next in size; the root of its nail is in a line with the tip of the little toe. Upper extremity.—Though the arm is more easily abducted from the side than is the fore limb in the Armadillo described by me, the extension of the forearm from the upper arm is, nevertheless, much limited, chiefly in consequence of the attachment of the strong platysma along the outer aspect of the former. I must here crave indulgence for a looseness and seeming uncertainty in my descrip- tions of certain muscles, seeing that I had no skeleton at hand while dissecting (a guide of which those alone know the value who have ever dissected much)—my sole osteological aid being derived from the plate of the skeleton of the Orycteropus contained in Cuvier’s ‘ Ossemens Fossiles,’ which I had always at my side when at work, and from a single short visit to the actual skeleton of this animal at the Museum of the Royal College of Surgeons. The more precise descriptions are founded upon more certain observations, and are, therefore, I hope, the more worthy of trust. Musculus sternalis hrutorum (or superficial layer of panniculus carnosus).—This is exceedingly well developed in the Orycteropus, and extends from the labial commissure to the lower extremity of the thorax. In the region of the head and neck its fibres are delicate and pale; but when the chest is reached, they become coarse and darker in colour, the bulk of the muscle being at the same time increased. At the commissure of the lips the fibres of the muscle appear to diverge, forming or sending contributions to a kind of orbicularis oris. Thence they pass, uniform in breadth, along the bnccal interspace between the upper and lower jaws; but on reaching the ' Rapp, op. cit. p. 13. Mr. Andrew Murray, however, in a “ Synonymic List of Species of Mammals and their Localities,” appended (p. 341) to his ‘ Geographical Distribution of Mammals’ (Lond. 1866), mentions three species of Orycteropus, namely:—0. .cEifiiopicus, Sund., S. Nubia, near the White Nile; 0. Capensis, Geoffir., Cafiraria, S. W. Africa; 0. Senegalensis, Less., Senegal. ^ In pi. .53 of ‘ Shaw’s Zoology’ (Mammalia), vol. i. part i. (Lond. 1800), the Orycteropus is plainly represented as plantigrade.