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 {Claviglis crassi- 

 caadatus Jent.t), 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 whatevei' 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 Graphkirus from Fernando Po 

 Avith 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 repi'esent a noi-mal specific variation, 

 and not a case of regeneration. 



Happily, however, further search had resulted in the discovery 

 of four specimens of a species of Grarpliiurus from the Cameroons, 

 sent by Mr. G. L. Bates, one of wdiich had a club-shaped tail, 

 with a styliform bony appendix, while the other three had normal 

 Doi-mouse 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-vertebrse 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 TS. 



Text-fig. 71 shows the tail of the Fernando Po Grcqikvurus, 

 Here, owing to the original bi-eaking having occurred nearer the 

 body, there appeared to be only about six normal vertebrje pre- 

 ceding the elongated terminal one. This latter was 11 mm. in 

 length, and instead of the knob at the end it had a slightly 

 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 pi-oved 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., ' Eegeneration,' p. 97 (1903). 



t Notes Leyd. Mns.x. p. 41 (1887). 



