On the difference in the mode of ossification of the first and other metacarpal and metatarsal bones / by Allen Thomson.

  • Thomson, Allen, 1809-1884.
Date:
[1868?]
Catalogue details

Licence: Public Domain Mark

Credit: On the difference in the mode of ossification of the first and other metacarpal and metatarsal bones / by Allen Thomson. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    2nd. The occasional and variable deviation from this ge- neral plan in man, and probably in some other animals, by the pi-asence of a more or less developed distal epiphysis on the first metacarpal and metatarsal bones; and the slighter indica- tion of a tendency to the formation of a proximal epiphysis on one or more of the other metacarpal bones. 3rd. The more complete and regular formation of a distal epiphysis on the first metacarpal or metatarsal bones of some animals, such as the kangaroo, koala and elephant, constitut- ing in them apparently the normal mode of o.ssification. 4th. The pecular condition observed in the seal, in the fore-foot of which animal the ossification follows the usual plan, while in the hind-foot distal epiphyses are fully develoijed on the first metatarsal bone and on all the phalanges, except the terminal ones. .5th. The tendency in the ornithorhynchus to the formation of ,lK)th distal and proximal epiphyses in all the metacnqjal and metatarsal lM)ncs. 6th. The fullest extension of these accessory points of os- sification occurring in the cetacea, in which distinct proximal and di.stal epiphyses exist in the metacarpal bones, and in the phalanges of the more developed digital series*. [Professor Thomson’s observations in the foregoing paper receive confirmation from s{K‘cimens of sections of the hand and foot from a girl, set. 10, which I placed .some years ago in the Anatomical Museum of the University of Cambridge. These show distinct epiphyses at the phalangeal, or distal, as well as ' In a communication which I have received from Dr Marie since tlie fore- going was in print, he informs me tliat in exainining young specimens of the Orang and Chimpansee he ha.s foiuid the state of the epiphyses of the first metn- car])ul and metatarsal bones the same as that which is most usimI in man. In the forellmb of the Otaria jubata, however, he has observed that tlie first meta- carpal bone (that of the pollex) hits not only the usual proximal epiphysis of largo size, but also a smaller distal one; and he has found the same to be the Wise in the metacarpal bone of the pollex in a Walrus considerably younger than the one I examined. But in both of these animals the first metatarsal bone pre- eentml only the usual proximal and no distal epii)hysis. These observations are interesting, when taken along with those I have recorded on the seal, as confirming the view of the inconstancy of the absence of a distal epiphysis in the first metacarpal or metatarsal bone, and in showing that we must distrust the position of the epiphysis to these bones as the ground of a homological distinction.