OCR Text |
Show 1899.] THE MYOLOGY OF THE EDENTATA. 1001 inserted into the hallux. Iu the Manidce (29, 32) the same description applies, but in one case (32) a small slip was given to the second toe as well as to the first. In the Orycteropodidce (35, 36) the muscle rises rather higher up from the fibula, and in both cases had a slip of communication with the extensor longus digitorum. Extensor longus digitorum.-In the Bradypodidce, Brad,ypus (1, 2, 4) and Cholcepus (8, 9) have the usual origin from just above the external condyle of the femur; but in Meckel's specimen of Bradypus (4) tibial and fibular origins were also met with. In Bradypus the insertion is never into the toes. In our specimen (1) the tendon divided into two slips, which were inserted into the bases of the innermost and outermost of the three developed metatarsal bones; it will be observed that the outermost of these is the same muscle as the human peroneus tertius. Cuvier and Laurillard's figure agrees very closely with our specimen, though they call this part of the muscle the peroneus brevis (6). In Humphry's specimen (2) the whole muscle was apparently inserted into the outermost metatarsal, while in Meckel's (4) it went to the innermost. In Cholcepus the insertion may be into the dorsum of all three toes (8, 10), or only iuto the second and third (9). Among the Myrmecophagidce, the origin is condylar in Myrmecophaga (1L) and Tamandua (14), but in Cyclothurus it rises from the tibia only (17, 19), or the tibia aud the fibula (20). The insertion is usually into the four outer toes, though in Cuvier and Laurillard's figure (21) it appears as if slips only went to the third and fourth toes, and in Couvreur and Bertaillon's specimen of Myrmecophaga into the three outer toes. In the Dasypodidce a femoral origin is never found, the muscle rising from the upper part of the fibula only, and being inserted into the four outer toes. This description applies to Dasypus (23), Tatusia (25), and Chlamydophorus (27, 28 a). In one specimen of Dasypus, however, (22) a slip was sent to the hallux as well as the other four toes; otherwise this specimen agreed with the rest. In the Manidce- the chief origin is from the tibia and fibula (29, 32, 33, 34), but in some specimens (32, 34) a feeble femoral origin is found. The insertion is into the outer three (29, 33) or four (32) toes. In the Orycteropodidce (35, 36) there is the normal femoral origin, and the insertion into the four outer toes (35, 36, 37). W e have already drawn attention to the connection with the extensor proprius hallucis. Extensor brevis digitorum.-In the Bradypodidce this muscle usually rises from the lower end of the fibula (1, 4, 6), but sometimes from the tarsal bones (presumably calcaneum) (2). It generally sends slips to all three toes (1, 2), but in one case (4) it only sent a tendon to the inner toe. In Cholcepus (8, 9,10) tbe muscle always rises from the tarsus and is inserted into the long tendons of all the toes. In the Myrmecophagidce the muscle always rises from the tarsus. In Myrmecophaga (11) and Tamandua (14,15) it sends slips to all five toes, but in Cyclothurus (17,19, 20, 21) only to the four |