AsTptimbefhi89™'}      Structure  of  Our  Cherry  Barks.  451 
mature  portions  of  the  inner  bark.  By  reason,  perhaps,  of  the 
abundance  of  bast  fibres,  the  radial  Assuring,  so  observable  in  all 
the  other  species  studied,  is  much  less  conspicuous  in  this. 
Owing,  probably,  to  the  fact  that  the  specimens  studied  were 
gathered  in  the  season  of  active  growth,  namely,  about  June  1st,  no 
starch  was  found  in  the  sections  examined. 
Oxalate  of  calcium  crystals  in  stellate  masses  are  abundant  in  the 
species. 
In  aromatic  quality  and  in  bitterness,  this  species  is  inferior  to  the 
Black  Cherry,  though  the  bitter  almond  odor  and  taste  are  much 
more  evident  than  in  any  of  the  other  species  thus  far  studied. 
Another  cherry  bark,  samples  of  which  were  sent  by  Professor 
Henry  G.  Greenish,  of  London,  has  been  examined  by  the  writer, 
and  found  to  resemble,  in  most  of  its  structural  characteristics,  that 
of  our  P.  Pennsylvanica.  It  differs  from  the  bark  of  this  species, 
markedly,  however,  in  some  particulars,  and  was  probably  derived 
from  one  of  the  unstudied  Pacific  Coast  species.  The  sample  was 
very  bitter,  somewhat  astringent,  and  slightly  aromatic.  Professor 
Greenish  states  that  the  sample  was  taken  from  a  quantity  which 
had  been  sent  to  the  London  market  as  Wild  Cherry  Bark. 
This  outline  of  the  studies  thus  far  made  by  the  writer  in  this 
genus  must  be  considered  merely  as  preliminary  to  a  more  complete 
account  which  he  expects  to  publish  at  a  future  time.  In  the  mean- 
time, it  is  hoped  that  the  descriptions  and  illustrations  here  given 
may  be  of  service  to  our  profession,  and  aid  in  emphasizing  the 
importance  of  the  study  of  the  histological  structure  of  drugs. 
The  writer's  thanks  are  due  to  Mr.  Henry  L.  Clarke,  of  the 
University  of  Chicago,  for  securing  for  him  authentic  specimens  of 
the  bark  of  Prunus  Virginiana. 
DESCRIPTION  OF  FIGURES. 
Fig.  1. — Transverse  section  of  bark  of  Prunus  serotina  magnified  75  diame- 
ters. The  specimen  was  from  a  stem  only  five  or  six  years  old.  cork,  prob- 
ably secondary  periderm;  b,  middle  or  green  layer  of  bark;  c,  clusters  of  stone 
cells  in  inner  portion  of  middle  bark;  d,  compressed  sieve  tissue  in  the  outer 
portion  of  bast  layer;  e,  a  medullary  ray;  /,  mass  of  stone  cells;  g,  fissure 
between  medullary  ray  and  bast;  k,  medullary  ray;  i,  cambium  zone;  <£,  duct 
in  mature  wood. 
Fig.  2. — Small  portion  of  longitudinal  section  made  well  toward  the  cambium 
zone  and  parallel  to  it.  Magnification  about  75  diameters,  a,  crystal  of  cal- 
cium oxalate;  b,  a  medullary  ray  cell  containing  starch;  c,  sieve  tube;  dy 
medullary  cell. 
