364  Histology  of  Hyoscyamus  Muticus.      { ^ig^$w;m' 
They  are  long  and  slender,  with  sloping  or  irregular  ends  (Fig.  2, 
m),  and  have  numerous  circular  or  slit-like  pores  which  may  be 
either  straight  or  oblique.  The  fibers  measure  from  10  to  25 
microns  in  width,  by  350  to  900  in  length. 
The  medullary  rays  are  composed  of  cells  very  regular  in  form. 
They  are  seldom  more  than  one  cell  wide,  and  contain  many  fine 
pores.    (Fig.  2,  r.) 
LEAVES. 
The  leaves  are  very  fragile  and  are  usually  in  much  broken  frag, 
ments.    However,  some  of  the  smaller  leaves  from  the  fruiting 
Fig.  3. — F,  Surface  view  of  epidermis  of  leaf,  under  surface,  showing  scars 
left  by  falling  trichornes  b;  s,  trichotne  from  stem  epidermis  ;  /,  epidermis  of 
leaf,  upper  surface  ;  v,  trichome  from  stem  ;  x,  trichome  from  inner  surface  of 
calyx  ;  /,  leaves. 
stalks  may  be  found  intact.  In  form  they  are  ovate,  lanceolate,  or 
oblong-lanceolate,  and  measure  30  to  80  mm.  in  length  by  15 
to  25  mm.  in  width.  They  have  either  acute  or  acuminate  apices  ; 
margins  entire  or  acutely  four  to  six-lobed,  and  bases  oblique  or 
inequilateral  (Fig.  j/).  The  veins  stand  out  conspicuousl  yon  both 
the  upper  and  under  surfaces  of  the  leaves,  but  are  more  prominent 
