AmdcJtober,Pi8f6,;m;}  North  American  Conifer ce.  561 
ata  occur  on  the  upper  surface  near  the  mid-rib,  and  toward  the  apex 
of  the  leaf. 
The  epidermis  was  found  to  be  composed  of  thick-walled  cells  of 
Fig.  4Q. — Cross-section  of  leaf  of  Abies  Fraseri,  magnified  75  diameters.  Ep 
Ep' ',  epidermis  ;  by,  hy/  hypoderma  ;  St. ,  stoma  on  lower  surface  of  leaf ;  sec.  /'., 
resin  passage  \f.  b.,  fibro-vascular  bundle ;  en,  endodermis. 
small  size.  A  hypoderma  composed  of  one  layer  of  thick-walled 
cells  occurred  on  the  upper  surface,  at  the  edges,  and  opposite  the 
mid-rib  on  the  lower  surface.   The  two  secretion  reservoirs  occurred, 
