Am.  Jour.  Pharm. 
November,  1904. 
Anatomy  of  Edible  Berries. 
541 
rule  the  lumen  is  much  narrower  than  the  walls  and  oftentimes  is 
reduced  to  a  mere  line.  Numerous  pores  connect  adjoining  cells 
and  some  pierce  the  walls  separating  these  cells  from  the  mesocarp. 
The  cells  range  in  length  up  to  0  5  millimeter;  the  thickness  of  the 
double  walls  is  from  0  005  to  0-02  millimeter. 
Testa  (Fig.  18,  S). — (1)  Mucilage  Cells  (Fig.  18,  aep). — The  outer 
layer  of  the  testa  consists  of  large  but  thin-walled  cells  rilled  with 
gelatinous  matter.  These  cells  are  about  0-09  millimeter  in  tangen- 
tial diameter,  but  often  have  a  radial  diameter  of  over  0-5  millimeter. 
On  the  outer  surface  they  are  usually  convex.  Owing  to  the  great 
size  of  the  cells,  this  coat,  although  but  a  single  cell-layer  thick, 
forms  a  considerable  part  of  the  bulk  of  the  seed.  - 
(2)  Parenchyma  (Fig.  18,  p). — Beneath  the  mucilage  cells  are 
several  layers  of  more  or  less  flattened  parenchymatous  cells  with 
intercellular  spaces.  The  inner  layers  are  smaller  than  the  outer 
and  more  strongly  flattened. 
(3)  Crystal  Layer  (Figs.  18  and  20  k). — In  surface  view  the  deep 
brown  thick-walled  cells  of  this  layer  are  sharply  polygonal  with 
diameters  from  0-008  to  0*020  millimeter.    The  middle  lamella  is 
Fig.  17. — Red  currant  endocarp  in  surface  view.    X  160. 
