Fig.  75,  portion  of  cross-section  of  stem  of  Pinus  palustris,  extendiug"from 
epidermis  nearly  to  the  cambium  zone,  magnified  75  diameters,  a, 'thick- 
walled  epidermis;  b,  hypodermal  tissues;  c,  area  of  thick-walled  cells^formed 
from  a  phellogen  layer;  t,  tannin  cell;  d,  stone  cell  in  cortex;  e,  tannin  cell; 
/,  bast  tissue. 
