326 



DR. C. F. SONNTAG ON THE ANATOMY, 



is not well diflerentiated from the levator anguli oris, but that is 

 not the case in my specimen ; it is only at their insertions that 

 these muscles are fused. Gratiolet (22) describes a mingling of 

 the fibres with those of the orbicularis and they cover the malar- 

 maxillaiy articulation. 



The zygomatic mass (text-fig. 25) in my specimen differs from 

 the muscles described by Ruge (42), Gratiolet (22), and Champ- 

 neys (11). In all the descriptions and published figures it is less 

 powerful, or the parts are more separate. In my specimen it is 

 the most powerful muscle in the face, and has three powerful 

 heads of origin, A strong bundle separates from the orbital part 

 of the orbicularis palpebrarum, the zygomaticus minor (Z.Mi) 



Text-figure 26. 



Deep muscles of the face. A.F.V : anterior facial vessels; F.N: facial nerve; 

 I.C.A : inferior coronary artery ; L.S.G : labial salivary glands ; MAS : 

 masseter; ORB.OR : orbicularis oris; S.D : Steusen's duct; S.T.V and 

 T.F.V : superficial temporal and transverse facial vessels ; T.M : temporal 

 muscle ; Z.F.V : zygomatico-facial vessels. Other letters in text. 



springs from the malar bone and temporal fascia, and the zygo- 

 maticus major (Z.Ma) arises from the anterior end of the zygoma. 

 The three heads unite to form a strong muscle an inch wide 

 blending with the muscles of the lips and angle of the mouth. 

 It probably does much more work than the proper levator anguli 

 oris. The quadratus lahii inferioris (text-fig. 26) has a lower 

 origin than in Man. It springs from the posterior half of the 

 lower border of the outer surface of the body of the mandible. 

 It is in contact with the masseter behind and receives fibres from 

 the platysma below. The fibres course upwards and forwards 

 and blend with those of the orbicularis oris. The anterior fibres 

 are fine and close together, and interlace in the front of the lower 

 lip with fibres of the opposite muscle. Running through the 



