Make  h.p.  sketch  (389)  of  the  palpebral  conjunctiva  near  the  level
of  the  fornix  conjunctivas.
(2)  THE  LACRIMAL  GLAND.    Study  a  stained  section  of  the  lacrimal
gland.     Sketch  l.p.   (390)   a  lobule,  showing  the  ducts  and  the  secre-
tory tubules.    Make  h.p.  sketches  (391,  a,  b,  etc,)  of  sections  of  tubules
at  several  stages  of  secretory  activity.    Where  are  the  accessory  lacrimal
glands  of  Krause?    Location  and  significance  of  the  gland  of  Harder?

XXI.    THE  EAR

(A)  THE  EXTERNAL  EAR.
(1)  AURICLE   (Pinna).     Study  l.p.  a  stained  section  of  the  lobule
of  the  ear,  including  adjacent  portion  of  the  pinna.     Note  the  absence
of  cartilage  in  the  lobule  proper,   and   the  abundant  adipose   tissue.
Sketch  (392).    Make  h.p.  sketch  (393)  of  portion  of  the  elastic  carti-
lage of  the  pinna.     Note  the  relatively  large  number  of  cells.
(2)  Study  l.p.  a  stained  section  of  the  cartilaginous  portion  of  the
External  Acoustic  Meatus.     Note  the  abundant  large  stiff  hairs,  seba-
ceous glands,  and  ceruminous  glands.    Sketch  (394).    Sketch  h.p.  (395)
a  transverse  section  of  the  secretory  portion  of  the  coiled,  simple  tubular,
ceruminous  gland.    Enumerate  differences  and  resemblances  between  the
ceruminous  glands,  the  sudoriparous  glands,  and  the  mammary  glands.
(B)  THE  MIDDLE  EAR  (Tympanum).
(1)   Study  l.p.  a  stained  radial  section  of  the  tympanic  membrane.
Note:  annulus  tympanicus;  umbo,  with  attached  manubrium  of  the


816  DIEECTIONS  FOE  LABOEATOKY  WOEK

malleus;  membrana  flaccida  (Shrapnell's  membrane)?  and  cutaneous
layer,  mucous  layer,  and  intermediate  radial  and  circular  collagen  fibers.
