1901.] 



THE ML'SCLES OF THE U^^GtJLATA. 



681 



In the Pig (8) it reaches to the 9th, in the Tapir (55) to the 8th, 

 iu the Horse (57) to the 10 or 11th, and in the Elephant (74) to 

 the 14th thoracic spine. It is noticeable that in many animals the 

 posterior fibres are not only inserted into the root of the scapular 

 spine, but also for some distance along the posterior (caudal) 

 margin. 



Latissimus doi'si. — This muscle rises from a variable number of 

 posterior thoracic spines, from the lumbar aponeurosis, and usually 

 from some of the posterior ribs. Its insertion is into the shaft of 

 the humerus below the neck with the teres major, and very often 

 some of its fibres pass across the axilla in front of the vessels and 

 join the insertion of the pectorals (see text-fig. 91). Lesbres (V.) 

 points out that in the Euminants and Solipeds the insertion is 

 lower down on the humerus than in most Mammals, but that in 

 the Pigs this is not the case. In most Ungulates the latissimus 

 dorsi is a feeble muscle, but in the TapiridiB it is very Avell 

 developed. The exact number of thoracic vertebrae from which 

 the muscle I'ises varies sometimes in different records of the same 

 animal and is often extremely difiicult to determine ; still, we 

 tabulate the origins for what they are worth : — 



Thoracic vertebra;. 



Hippopotamus (1). ? number. 



Pig (8) ? „ 



Pig (11) 5th to last. 



Peccary (18) .... ? 



Peccary (14) .... 5th to last. 



Chevrotain (20) . . Last 5 (9-13) 



Chevrotain (21) . . Last 7 (7-13). 

 Brocket (28) .... ? 



Giraffe (30) .... ? 



Ox (35) Last 4. 



Sheep (40) ; Last 4. 



Sheep (43) Last 8. 



Sheep (45) Last 4 (10-13). 



Antelope (49 ) . . . . Last 6 (9-14). 



Tapir (54) ? 



Horse (57) Last 4. 



Horse (56) Last 14 or 15. 



Hyrax (67) ? 



Hyrax (68) Last 11 (10-20). 



Hyrax (71) ? 



Elephant (74) .. ? 



Eibs. 

 Posterior ones. 

 Posterior 4. 

 None. 

 Posterior 4. 



9 



None. 



Posterior ribs. 

 Last 4 ribs. 

 Last 4 ribs. 



? 



■? 

 Last 3. 



Eeeble costal origins. 

 Feeble costal origins. 

 Last 10. 



9 



12th and 13th. 

 No ribs. 

 No ribs. 

 No ribs. 

 Last 6 (9-14). 



With regard to the insertion, slips were found crossing the axilla 

 in front of the great vessels in the following animals : — Brocket 

 (27), Sheep (41, 45), Antelope (49), Hyrax (68) (see text-fig. 91), 

 and apparently Elephant (74, 79). 



The nerve-supply in the Pig, Deer, Sheep, Antelope, Elephant, 

 and Horse is from the long subscapular nerve. 



