54^  The  Apocynacecz  in  Materia  Medica. 
ment  of  plucking,  but  if  the  fruit  is  maintained  firmly  bound  with  a 
band  during  desiccation,  the  ventral  face  shows  a  simple  cleft,  long, 
and  straight,  fixed  by  the  placentary  plates  which  it  separates.  The 
seeds  are  completely  concealed,  but  the  more  oftea  the  suture 
enlarges  leaving  exposed  the  contents.  The  placental  plate  is  thin, 
fragile,  papyraceous,  color  dirty-white  or  yellowish-white  or  pale- 
yellow,  smooth  and  shining  upon  the  internal  face,  dull  toward  the 
exterior,  or  it  is  covered  with  a  fine  yellow  membrane  ordinarily  not 
adherent.  This  is  very  easily  detached  from  the  ligneous  part  of 
the  fruit,  and  is  often  cut  in  slender  strips.  The  margins  of  the 
carpels  are  then  bevelled  and  slightly  turned  inward.  The  internal 
face  of  the  pericarp  deprived  of  the  seeds  is  entirely  different,  the 
color  much  more  clear,  brownish  to  greenish-yellow,  it  is  glossy, 
satiny  and  to  the  touch  soapy  ;  it  is  smooth  and  very  uniform. 
Upon  a  transverse  section  of  the  pericarp  we  perceive  two  regions 
very  unequal ;  the  external  much  thicker,  is  brown,  a  little  deeper 
towards  the  exterior,  marked  by  white  points  quite  easily  seen.  The 
internal,  very  thin  but  very  tough,  is  yellowish,  more  clearly  dis- 
tinct than  the  other,  from  which  it  is  easily  separated.  In  com- 
merce, the  fruits  are  often  reduced  to  this  internal  layer. 
Structure  of  the  Pericarp. — The  external  zone,  thick  and 
brown,  is  constituted  by  a  parenchyma  of  irregular  cells,  upon 
section,  very  flattened,  sinuous,  containing  the  brown  coloring  mat- 
ter.   In  this  tissue  we  find  : 
(1)  The  fibro-vascular  fascicles. 
(2)  The  fascicles  of  long  fibres,  yellowish-white,  very  strongly 
>sclerified,  with  linear  lumen. 
;(3)  Abundant  laticiferous  vessels  with  a  colored  juice,  more  or 
less  red,  with  thin  walls,  a  sinuous  passage. 
The  internal  zone,  yellow,  brittle  and  thin,  is  formed  of  sclerotic 
elements,  very  difficult  to  cut ;  the  fibres  which  constitute  this  are 
disposed  in  two  directions;  the  external  (1  or  2  layers)  longitudi- 
nally, the  internal  transversely,  these  last  somewhat  entangled. 
The  placental  plates  are  proportionately  richer  in  fibres  and  poorer 
in  parenchyma.  The  placentas  present  only  the  longitudinal  fibres, 
the  external  side  from  which  departs  the  funicules,  with  trachese 
and  laticiferous  vessels,  and  on  the  internal  side  the  membrane  is 
limited  by  one  layer  of  very  large  fibres.  The  thin  membrane 
which  covers  the  placentas  with  two  cellular  planes*  with  here  and 
