546 
Fruit  of  Cocos  Nucifera. 
f  Am.  Jour.  Pharm. 
1  November,  1901. 
Rosanoff1  found  stegmata  in  twelve  species  of  palms,  and  Kohl,2 
who  has  made  an  exhaustive  study  of  the  subject,  in  twenty-three 
additional  species.  Neither  author  mentions  Cocos  nucifeta,  but 
Kohl  found  in  C.  flexuosa  stegmata  with  silicious  contents  which 
answer  the  description  of  those  in  coir  fiber. 
ft.  Bast-fibers  (Figs,  5  and  6,f)  completely  surround  the  bundle. 
They  vary  in  length  up  to  2  m.m.  and  in  diameter  up  to  -03  m.m. 
The  double  cell  walls  are  from  one-half  to  one-sixth  the  breadth  of 
the  lumina,  with  conspicuous  pores  and  diagonal  markings.  In 
longitudinal  section  the  walls  adjoining  the  stegmata  are  sinuous 
in  outline,  due  to  the  depressions  into  which  the  stegmata  are 
fitted.  On  the  edge  of  the  xylem  the  bast-fibers  pass  into  tracheids 
(Fig.6,t). 
y.  Xylem  (Fig.  5,  x;  Fig.  6).  The  elements  are  tracheae,  tra- 
cheids and  various  forms  intermediate  between  tracheids  and  bast- 
fibers,  and  tracheids  and  parenchyma. 
The  tracheae  range  in  diameter  up  to  -05  m.m.,  the  larger  (found 
in  large  fibers)  being  reticulated  (Fig.  6,  r)  or  scalariform-reticulated 
(sc),  the  smaller  (found  both  in  large  and  small  fibers)  being  spiral 
or  reticulated  spiral.  Among  the  spiral  tracheae  one  finds  con- 
siderable variation  both  as  to  their  size  and  the  steepness  of  their 
spirals.  As  might  be  expected,  those  in  the  protoxylem  often  have 
delicate  spirals  with  turns  wide  apart.  An  intermediate  form  is 
shown  in  Fig.  6  (sp). 
The  tracheids,  distinguished  from  the  tracheae  by  the  transverse 
or  diagonal  partitions  and  by  their  smaller  size  and  thinner  walls, 
likewise  display  an  interesting  diversity  of  size  and  form.  Among 
these  are  forms  with  large  pits  and  curious  reticulations  (Fig.  6,  tr) 
also  transitional  forms  between  tracheids  and  bast-fibers  (t)  on  the 
one  hand,  and  tracheids  and  parenchyma  on  the  other. 
d  Phloem.  Sieve  tubes  and  cambiform  cells  make  up  the 
phloem  (Fig.  5,  ph). 
Measured  in  cross  sections,  the  diameters  of  the  sieve  tubes  vary 
up  to  -03  m.m.  In  longitudinal  sections  it  may  be  seen  that  the 
sieve  plates  are  either  at  right  angles  to  the  walls  or  oblique  and 
that  oftentimes  they  are  covered  with  callus  through  which  run  a 
few  indistinct  pores  (Fig.  6,  s). 
1  Bot.  Ztg.,  1871,  p.  749. 
2  Kalksalze  und  Kieselsdure  in  der  Pflanze,  Marburg ;  1889,  p  289. 
