Am.  Jour.  Pharm.1 
September,  1899.  / 
Gelsemiiim  Sempervirens,  Ait. 
429 
the  coiled  hyphae  and  the  fructifications  of  the  fungus.  Starch  is 
usualiy  absent  in  the  cells  inhabited  by  the  fungus.  In  the  root  of 
a  seedling  about  six  weeks  old,  the  fungus  was  already  well  estab- 
lished in  many  cortex  cells. 
HISTOLOGY  OF  THE  SEEDLING. 
The  diarch  condition  of  the  root  is  continued  in  the  hypocotyl, 
and  it  may  at  once  be  stated  that  the  median  plane  of  the  two  pro- 
toxylem  masses  corresponds  to  the  median  plane  of  the  cotyledons. 
The  spiral  tracheae  of  each  end  have  at  first  a  Y-shaped  arrange- 
ment, the  arms  of  the  Y  pointing  toward  each  other,  thus,  — < 
Fig.  3. 
> — ,  but  as  the  hypocotyl  increases  in  age,  the  cells  of  the  arms 
move  apart,  taking  a  lateral  position,  with  the  phloem  external  to 
them,  usually  two  patches  to  each  side.   This  is  illustrated  in  Fig. 
As  differentiation  proceeds  more  spiral  tracheae  are  interpolated 
between  those  already  formed,  so  that  a  continuous  ring  ot  proto- 
xylem  is  finally  present.  The  phloem  consists  of  small  patches  of 
finely  divided  cells,  along  the  outer  margin  of  the  sides  of  the 
wood,  but  is  not  yet  continued  around  the  ends.  At  the  level  of 
the  cotyledons,  the  phloem  from  the  sides  bends  toward  the  ends, 
and  the  zone  is  thus  completed.  No  recognizable  internal  phloem 
could  be  distinguished  in  the  young  hypocotyl. 
