| OCR Text |
Show 1894.] MYOLOGY OF RODENTS. 269 In Cavia cobaya there are two slips, the radial goes to the index and middle, the ulnar to middle, ring, and httle fingers. In Pteromys and Arctomys the radial slip goes to all the fingers, while the ulnar only goes to the middle and ring. Fig. 4. LEXT.COM. DIG.. Left fore foot of Castor canadensis (extensor tendons). Extensor Minimi Digiti.-The extensor minimi digiti rises from the external condyle in common with the extensor communis digitorum, and is usually inserted into the tendons of that muscle on the dorsum of the 4th and 5th digits. Its tendons are also usually connected to the ulnar sesamoid bones on the palmar surface of the metacarpo-phalangeal joints. In the following animals the insertion differed from the above description:- Sphingurus and Sciurus to 3rd, 4th, and 5th digits ; Chinchilla, Pteromys, and Castor to 5th only. In Aulacodus the muscle was completely fused with the extensor communis. From the difference in the number of tendons in animals otherwise closely allied I should suspect this muscle of being liable to a good deal of individual variation. |
