PHYSIOLOGY, AND PATHOLOGY OP THE CHIMPANZEE. 



327 



muscle are branches of the inferior labial artery (I.L.A), and 

 the mental branch of the inferior dental nerve emerges from 

 the mandible underneath it. Champneys (11) states that this 

 muscle is not differentiated. 



Text-figure 27. 



Muscles of the eyelids (A), eyes (C-F) and nose (G) : conjunctiva (B). C: cilia; 

 CONJ: conjunctiva; E: eyelids; E.N.N: external nasal nerve; F.M : 

 frontalis ; I.O : inferior oblique in the Chimpanzee (C) and Man (D) ; I.T.L : 

 internal tarsal ligament ; L.T.R: lateral tarsal raph^ ; M.L.GDS: Meibomian 

 glands ; O.P : orbitalis ; P.S : plica semilunaris ; P.P : palpebralis ; L.P.S : 

 levator palpebrae superioris of Man (E) and the Chimpanzee (F) ; S.O : 

 superior oblique muscle. 



The triangularis (text-fig. 25, tri.), although figured as a promi- 

 nent muscle by Ruge (42), is represented by a few broad fibres 

 passing from the platysma to the angle of the mouth. 



The orbicularis oris is composed of fibres from all the facial 

 muscles except the levator labii superioris alseque nasi ; and it 



22* 



