26 ELEMENTARY PHYSIOLOGY. [l. 



G. In the dog, reflect the skin of the head, note 

 again the position of the subinaxillary gland 

 (cp. C. 28 d.) as seen from the surface; it lies 

 between two large branches of the jugular vein ; 

 attached to the inner part of the posterior 

 extremity of the lower jaw will be seen the 

 digastric muscle ; clear away the connective 

 tissue surrounding it, cut it through, taking 

 care not to injure the parts beneath, and 

 reflect the cut ends; the submaxillary duct 

 (duct of \Vharton) will be seen running from 

 the gland, trace it forwards, it runs underneath 

 (dorsally of) a muscle with transverse fibres, the 

 mylohyoid, cut through this, turn the lateral 

 part as far back as possible, taking care that 

 the fascia on its lower surface is not attached 

 to it and follow the duct forwards. 



7. Attached to the anterior end of the submaxillary 

 gland and stretching for some little way along 

 its duct will be seen the smaller sublingual 

 gland, from this runs the sublingual duct, 

 alongside and laterally of tho duct of the 

 submaxillary gland. 



8. A short distance from the lower border of the 

 mylohyoid muscle the lingual nerve will be seen 

 crossing the ducts and running on to the tongue : 

 pull the tissues on which the lingual rests well 

 away from the jaw, about three quarters of an 

 inch centrally of the point where the lingual 

 crosses the ducts, it will be seen to give off a 

 small nerve the chorda tympani. This curves 

 towards the ducts and then runs alongside them 

 towards the sublingual and submaxillary glands. 



