As"ptJe0mberiT9"-}      Structure  of  Our  Cherry  Barks.  437 
small  whitish  lenticels,  and  the  corky  layer  may  be  readily  peeled 
off  transversely  in  a  thin,  papery  layer,  exposing  the  deep  green 
middle  bark  beneath.  The  corky  layer  of  the  root,  which  is 
somewhat  lighter  colored,  begins  to  fissure  and  exfoliate  much 
earlier,  and  when  the  cork  is  removed  it  exposes  a  middle  layer 
which  is  at  first  white,  but,  on  exposure,  soon  turns  ochreous 
Fig.  2. — Longitudinal  tangential  section  of  inner  bark  of  Prunus  serotina. 
brown.  The  leaves  are  short-petiolate,  with  thin,  lanceolate, 
toothed,  deciduous  stipules,  and  elliptical,  oblong,  or  oblong- 
lanceolate,  taper-pointed,  appressed-serrulate  leaves,  which  are 
usually  obtuse,  but  sometimes  acute  at  the  base,  and  commonly  have 
a  pair  of  glands  on  the  petiole  near  the  insertion  of  the  blade. 
They  are  smooth  on  both  surfaces,  thickish,  and  deep  and  some- 
