1903.] THE MUSCLES OF THE UXGULATA. 279 



on Elephant's muscles, is into the bases of all the metatarsal 

 bones from the fifth to the fii-st. The nerve-supply is from the 

 external popliteal in the Duiker-bok, Ohevrotain, Sheep, and 

 Elephant. 



Peroneas hrevis. — In animals such as the Lemur and many of 

 the Rodents, where a complete set of peroneals is found, the 

 peroneus brevis runs from the fibula to the base of the fifth 

 metatarsal bone, while the peronei quarti et quinti digitorura 

 pass on to the dorsum of the phalanges. Judging by this 

 standard, we have no hesitation in saying that we have as yet 

 seen no reason to believe that a peroneus brevis is eA^er pi-esent 

 in Ungulates, except, perhaps, in the Elephant. It is described 

 by a great many authors, but in every case we have found that 

 what they call peroneus brevis is continued on to the dorsum of 

 the fourth (annularis) digit, and does not even end in the fourth 

 metatarsal bone. When one realises how commonly the fibula and 

 the fifth metatarsal ai'e suppressed in this order, one is prepared 

 to expect a similar suppi-ession of the peroneus brevis. In 

 Pateison and Dun's Elephant a muscle was found which they 

 call pei'oneus minimus, which rose fi'om the fibu.la and was 

 inserted into the calcaneum and base of the fifth metatarsal; this 

 we believe is a peroneus brevis, and the only example of it found 

 in the Ungulata. The authors call it peroneus mininuis because 

 they have fallen into the common mistake of calling the peroneus 

 quai-ti digiti the peroneus brevis. 



Peroneus quarti digiti. — This muscle is always present in 

 Ungulates. When the fibula is well developed, as in Hyrax and 

 the Elephant, it rises from the middle thii-d of that bone, but 

 when, as in most Ungulates, there is only the head of the bone 

 present, the muscle rises from that and often from the adjacent 

 part of the tibia. The tendon usually runs in a groove on the 

 outer side of, not behind, the external malleolus, and is inserted 

 into the extensor longus digitorum tendon of the annularis. In 

 the Horse, however, with the suppression of the annularis, the 

 peroneus quarti digiti, which is the only peroneal present, shifts 

 its insertion on to the dorsum of the medius. We have records 

 of the peroneus quarti digiti under various names in the following 

 representative series of animals: — Hippopotamus (1, 3), Pig (4, 

 6, 7, 11), Peccary (13, 14), Camel (17), Ohevrotain (20, 22, 24), 

 Deer (25, 26, 27, 29), Elk (30), Musk-Deer (31), Ox (35, 36, 38, 

 40) (in the last-named animal, 40, the tendon was inserted into 

 the middle phalanx of the annularis toe), Sheep (41, 42, 43, 47, 

 48), Goat (50, 51), Antelope (54, 55), Tapir (58, 62), Horse (63, 

 64, 65), Rhinoceros (71), Hyrax (74, 75), and Elephant (81, 85). 

 The nerve-supply is always the musculo-cutaneous. 



Peroneus quinti digiti. — This mviscle is present in the Hippopo- 

 tamus (1, 3) and sometimes in the Pig (4), Musk-Deer (31). and 

 Elephant (81, 85). It rises from the upper part of the fibula 

 and is inserted into the extensor tendon of the fifth digit. Its 

 nerve-supply is the musculo-cutaneous. 



