The  curves  made  by  the  artery,  and  its  tortuosity  under  the  tongue,
are  obviously  for  the  purpose  of  allowing  the  unrestricted  elongation
of  this  organ.  In  the  first  part  of  its  course  it  is  comparatively
super Gcial ;  in  the  middle  it  is  deeply  placed  between  the  hyo-
glossus  and  the  middle  constrictor  of  the  pharynx ;  in  the  last
part — that  is,  beneath  the  tongue — it  is  situated  between  the  lin-
gualis  and  the  genio-hyo-glossus.
The  relative  position  of  the  lingual  artery  and  nerve  is  as  follows.
Near  the  apex  of  the  comu  of  the  os-hyoides  the  nerve  lies  nearly
parallel  to  and  above  the  artery ;  subsequently  they  are  separated
by  the  hyo^lossiis  muscle,  the  nerve  being  the  more  superficial ;


B1tANCHE8  OF  THE  EXTERNAL  GAROTED.  139

but  at  the  anterior  border  of  tbe  muscle  we  find  the  artery  ascend-
ing,  beneath  the  nerve,  to  the  under  surface  of  the  tongue.
The  branches  of  the  lingual  artery  are —

a.  The  hyoid,  a  small  artery  which  runs  along  the  upper  border
of  the  os-hyoideSy  supplying  the  muscles.
6.  The  dorsaUs  lingtue,  small  branches  which  ascend  under
cover  of  the  hyo-glossus  to  supply  the  back  of  the  tongue  and  the
tonsils.
