| OCR Text |
Show 492 MR. OLDFIELD THOMAS OX [Dec. 12, the tails of Lizards. Any form of regeneration of osseous parts had been hitherto quite unknown among Mammals*'. The external tail of this Dormouse was about 5 cm. in length, and was thickened, fat, and club-shaped terminally, where its hairs, 9 or 10 mm. long on its basal portion, lengthened to 25- 28 mm. It formed therefore a sort of bushy club, quite different to the simple distichous tail of a normal specimen. A similar tail had been described in a Liberian Dormouse (Glaviglis crassi-caudatus Jent.f), but the bones had not been examined. On extracting the bones of the tail, they proved to be of an appearance so closely similar to that found in cases of regeneration in Lizards, that Mr. Thomas had no doubt whatever that they were of the same nature, and search for further examples fully confirmed this opinion. For, firstly, among the collections of the British Museum there was found an example of a small Grapkiurus from Fernando Po with a similar club-shaped, bushy tail, always hitherto looked upon as accidentally broken, and this on being opened proved also to contain a long regenerated terminal " style," as shown in fig. 71. But this specimen, like that from Central Asia, was open to the objection that being a single individual from an out of the way locality, it might conceivably represent a normal specific variation, and not a case of regeneration. Happily, however, further search had resulted in the discovery of four specimens of a species of Graphiurus from the Cameroons, sent by Mr. G. L. Bates, one of which had a club-shaped tail, with a styliform bony appendix, while the other three had normal Dormouse tails. This series thus put beyond cavil the inference already arrived at as to the abnormal character of the specimen exhibited. Text-fig. 70 shows the tail-vertebrae and regenerated appendix of the Central-Asian Eliomys, now exhibited. The caudal column consisted of 11 normal vertebra', while the proximal end of the 12th was also normal. But distally this vertebra thinned out into a long slender style, its total length being 15 mm. and its diameter (after the basal 2 mm.) rather less than 1 mm. At its tip there was a constriction succeeded by a small thickened knob. The preceding vertebra measured 6‘2 x 1 '8. Text-fig. 71 shows the tail of the Fernando Po Graphiurus. Here, owing to the original breaking having occurred nearer the body, there appeared to be only about six normal vertebra? preceding the elongated terminal one. This latter was 11 mm. in length, and instead of the knob at the end it had a slightlv crooked point. The drawing would show the position of the point relative to the general body of the tail. On breaking the terminal spike across, its section proved to be * " In the Mammals neither the legs nor the tail nor the jaws regenerate, although several of the internal organs . . . . have extensive powers of regeneration."-Morgan T. H., ‘ Regeneration,' p. 97 (1903). f Notes Leyd. Mus. x. p. 41 (1887). > |
