434  Anatomy  of  Edible  Berries.  {AS^{^fSSt 
from  0-008  to  0*020  millimeter  in  diameter.  The  monoclinic  crystals 
are  always  simple,  and  are  especially  striking  when  illuminated  with 
polarized  light.  The  diameter  of  each  crystal  is  about  half  that  of 
the  cell  in  which  it  is  contained. 
(4)  Outer  Endocarp  {Fig.  3,  If). — This  layer,  forming  the  larger 
part  of  the  pericarp,  is  made  up  of  five  or  more  thicknesses  of 
sclerenchymatous  fibers  longitudinally  arranged.  As  seen  in  cross 
section,  the  cell  walls  are  about  as  thick  as  the  diameter  of  the 
lumen.    The  pores  are  clearly  evident  in  longitudinal  section. 
(5)  The  Inner  Endocarp  (Fig.  J,  qf)  consists  of  the  same  elements 
as  the  outer  endocarp,  but  is  only  one  or  two  cell  layers  thick,  and 
the  cells  are  arranged  transversely.  On  the  dorsal  side  some  of 
the  fibers  of  this  layer  extend  radially  through  the  outer  endocarp, 
thus  facilitating  the  rupture  of  the  pericarp  during  sprouting. 
br 
Fig.  4. — Strawberry  testa  and  endosperm  in  surface  view.  Signification  of 
letters  same  as  in  Fig.  3.    X  300. 
Testa. — (1)  The  Epidermis  (Figs.  3  and  4,  ep)  is  made  up  of  thin- 
walled  cells,  which  in  surface  view  are  polygonal,  in  section  quadrilat- 
eral. The  cell  walls  are  exceedingly  thin,  but  are  strengthened  by 
thickened  bands,  resembling  those  of  spiral  and  recticulated  vessels. 
They  differ,  however,  from  the  latter  in  that  they  do  not  pass  com- 
pletely around  the  cell,  but  are  wanting  on  the  outer  surface,  so 
that  in  mounting  a  preparation  the  outer  wall  often  collapses  and  the 
side  walls  fall  down,  presenting  the  appearance  shown  in  Fig,  4. 
This  layer  is  difficult  to  make  out  in  cross  section,  but  is  readily 
studied  in  surface  view. 
(2)  Brown  Layer  (Figs,  3  and  4,  br). — The  second  layer  of  the 
testa  is  composed  of  elongated  brown  cells,  which  pass  transversely 
about  the  seed.    Transverse  sections  of  these  cells  are  quadrilateral, 
