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Structure  of  Geranium  Maculatum.  { 
Am.  Jour.  Pharm 
November,  1894. 
If  the  rhizomes  are  gathered  in  the  autumn  of  the  year,  when 
the  vegetative  growth  of  the  season  has  been  completed,  the  paren- 
chymatous tissues  will  be  found  heavily  charged  with  starch.  If 
gathered  in  spring,  when  vegetation  is  well  advanced,  however,  the 
starch  may  have  wholly  disappeared,  having  been  employed  in  the 
development  of  the  leaves  and  above-ground  stems. 
If  sections  be  treated  under  proper  conditions  with  a  solution  of 
ferric  chloride,  or  with  a  solution  of  ammonio-ferric  alum,  the 
Fig.  4. 
copious  blue  black  precipitate  produced,  due  to  the  presence  of 
tannin,  will  be  found  to  be  much  more  abundant  in  some  cells  than 
in  others,  though  there  are  few  cells  wholly  destitute  of  it.  Those 
in  which  the  precipitate  is  most  copious  seem  indeed  to  be  chiefly 
devoted,  to  the  secretion  of  tannin,  and  they  may  appropriately  be 
called  tannin  cells.  Besides  tannin,  however,  they  usually  contain 
some  starch  and  proteid  matter.  They  commonly  occur  in  clusters 
of  two  or  more,  and  these  clusters  are  scattered  irregularly  through 
the  parenchymatous  tissues  of  the  pith  and  bark.    If  the  section  be 
