43°"  Structure  of  Our  Cherry  Barks.  {^pfembef.m^' 
cultivated  in  San  Francisco  and  vicinity,  and  perhaps  in  the  vicinity 
of  some  other  cities  of  the  Pacific  Coast.  '  It  seems  to  attain  its 
fullest  development  in  the  valley  of  the  Ohio,  where  it  sometimes 
attains  the  height  of  100  feet  and  its  trunk  a  diameter  of  4  feet. 
Ordinarily,  however,  it  is  smaller,  with  a  trunk  18  inches  in  diame- 
ter and  a  height  of  50  or  60  feet.    Its  close-grained  heartwood 
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Fig.  1. — Transverse  section  of  the  stem  bark  of  Prunus  serotina. 
which  is  capable  of  taking  a  high  polish,  and  which  has  a  light  red 
color,  deepening  with  age,  is  highly  valued  for  cabinet  and  orna- 
mental work.  The  bark  of  the  trunk  is  blackish-brown  and  rough 
exteriorly,  the  exterior  corky  layers  exfoliating  transversely  in 
thickish  but  rather  narrow  pieces.  The  bark  of  the  twigs,  however, 
is  smooth  or  even  glossy,  dark  reddish-brown,  thickly  punctate  with 
