390 
NOTE  ON  A  FALSE  JALAP. 
the  fleshy  nature  of  the  root,  is  modified  in  drying.  The  epi- 
dermis is  exceedingly  wrinkled,  and  has  a  mottled  brown  color 
resembling  jalap,  varying  from  light  brown  to  almost  black.  The 
odor  of  the  tubers  is  almost  precisely  that  of  true  jalap,  and  very 
decided,  and  this  character  renders  it  a  dangerous  adulteration, 
as  it  is  more  difficult  to  imitate  the  odor  of  jalap  than  any  other 
of  its  properties.  The  tubers  are  not  scored  with  a  knife,  like 
jalap  often  is,  to  facilitate  drying.  The  interior  is  spongy  in 
texture,  no  indications  of  concentric  tissues,  as  in  jalap,  and  no 
visible  resinous  deposit.  It  is  easily  impressed  with  the  nail, 
and  has  a  tolerably  uniform  light  drab-brown  color.  Desiring 
to  know  more  of  its  structure  and  botanical  characters,  I  sub- 
mitted a  sample  to  Prof.  John  M.  Maisch  for  microscopic  ex- 
amination, who  kindly  makes  the  following  report : 
"  The  surface  is  composed  of  suberous  layer  in  about  ten  rows 
of  cells,  the  walls  of  which  are  partly  dark  brown  and  partly 
brownish-yellow.  The  parenchyma  of  the  bark,  which  occupies 
five  to  six  times  the  thickness  of  the  former  layer,  consists  of 
numerous  cells  stretched  tangentially,  and  is  not  interspersed 
with  medullary  rays.  Inside  the  cambium  line  we  find  the 
parenchyma  composed  of  more  regular  cells,  and  containing  ves- 
sels surrounded  by  soft  ligneous  prosenchyma,  the  bundles  show- 
ing upon  cross  section  very  short,  bent,  or  somewhat  irregularly 
twisted  lines,  which  are  scarcely  concentrically  arranged,  and 
without  any  distinct  or  very  apparent  radiating  arrangement. 
The  parenchyma  of  the  bark  and  body  of  the  tuber  contains 
much  starch,  but  no  resin  cells,  nor  have  I  yet  found  crystals  in 
either  tissue. 
"  The  structure'  of  the  tuber  is  therefore  very  different  from 
that  of  the  so-called  'jalap  stalks,'  the  tubers  of  Ipomoea  Oriza- 
bensis,  which  have  a  distinctly  radiating  arrangement  of  the 
ligneous  bundles.  It  differs  from  true  jalap  in  the  total  absence 
of  the  resinous  zones  and  cells  ;  but  if  these  are  left  out  of  con- 
sideration there  is  a  striking  resemblance  between  this  false 
jalap  and  the  true  tuber,  as  the  simultaneous  examination  of  sec- 
tions of  both  will  show.  The  false  jalap  in  question  has  no 
similarity  whatever  with  the  roots  and  tubers  which  have  been 
