PHYSIOLOGY, AND PATHOLOGY OF THE CHIMPANZEE, 337 



Man from the oblique line on the thyroid cartilage and from the 

 side of the cricoid. Its fibres sweep more or less upwards, 

 overlap the lower border of the middle constrictor and blend 

 with the opposite muscle in the mid-dorsal line. It has no origin 

 from the first tracheal ring as in Gratiolet's specimen (22). 



The stylo-pharyngeus (text-fig. 32, S.P) arises from the tendon 

 of the stylo-glossus, but Gratiolet (22) states that it rises from 

 the base of the styloid apophysis. It splits up into bundles some 

 of which are inserted into the superior and middle constrictors, 

 others passing between these muscles and radiating in the wall 

 of the phaiynx. The glosso-pharyngeal nerve hooks round it 

 and sends it a well-marked branch. 



The levator palati and tensor palati (text-fig. 29 B) arise by 

 a. strong, common musculo-aponeurotic origin from the apex of 

 the petrous temporal bone, the under surface of the Eustachian 

 tube and the scaphoid fossa. So the separate origins of the 

 muscles have fused in this animal. The levator palati (L.P) 

 runs downwards and forwards and spreads out between the 

 layers of the palato-pharyngeus. The tensor palati (T.P) is 

 even more horizontal. Its tendon winds round the pterygoid 

 hamulus and is inserted by several small tendinous and fascial 

 bundles in the palatal aponeurosis. The complete limits of the 

 palato-pharyngeus (P.P) could not be accurately made out, and 

 the palato-glossus hardly exists. The azygos uvulce (A.U) ends 

 posteriorly in membrane as pointed out by Gratiolet (22). 



The thyro-hyoid runs from the entire width of the thyroid ala 

 to the under and outer surfaces of the body and great cornu of 

 the hyoid bone. Its nerve from the hypoglossal is well marked. 



The scalenus anticus arises from the anterior tubercles of the 

 transverse processes of the third, fourth, and fifth cervical 

 vertebrse, but others have given its origin from 4, 5, and 6. 

 It is connected by a tendon to the rectus capitis anticus major. 

 It is inserted as in Man, the tubercle on the first rib being lateral 

 to the chondro- costal junction. The scalenus medius and scalenus 

 posticus arise as in Man. They unite to foi'm a flat sheet which 

 courses downwards to be attached to the outer surfaces of the 

 first five ribs. The fusion and extent are greater than that 

 described by Gratiolet (22) and others. It is crossed posteriorly 

 by the slips of insertion of the upward continuation of the sacro- 

 spinalis. 



The omo-trachelian runs as usual from the transverse process 

 of the atlas to the upper and outer aspect of the acromion. 

 It has been recorded by some as being not an omo-trachelian, but 

 as an acromio-basilaris. 



Muscles and Fascice of the Back, 



The fascia covering the trapezius and latissimus dorsi is of 

 great strength, especially below. It is attached above to the 

 occipital crest, mesially to the vertebral spines and below to the 



