Am,Mayr;S4arm-}         Notes  on  the  Genus  Myrica.  223 
layer  and  a  broader  sieve  portion.  A  crescent-shaped  layer  of  bast 
cells  extends  beyond  this,  and  in  addition  to  this  the  mechanical 
system  is  strengthened  by  prominent  layers  of  collenchyma  cells 
situated  below  the  epidermis  and  on  either  side  of  the  midrib.  The 
palisade  and  fundamental  parenchyma  cells  are  well  filled  with 
chlorophyll.  The  parenchyma  toward  the  lower  surface  is  of  a 
spongy,  open  character. 
The  stem,  on  transverse  section,  exhibits  a  thin  bark,  the  outer 
portion  of  which  easily  breaks  away.  The  pith  is  irregular  in  shape 
and  somewhat  eccentrically  located.  The  pith  parenchyma  cells 
possess  somewhat  thickened  walls,  marked  with  distinct  pittings. 
The  wood  is  in  numerous  narrow  wedges,  separated  by  narrow  medul- 
lary rays  extending  well  into  the  middle  bark.  The  spring  and  fall 
deposits  of  wood  are  well  marked  layers,  and  the  section  shown  in  Fig. 
2,  made  from  the  stem  of  a  plant  collected  during  the  recent  warm 
weather  in  March,  shows  that  the  deposition  of  the  more  open  spring 
wood  had  already  commenced.  The  cambium  zone  is  narrow  and  is 
subtended  by  a  rather  broad  phloem  layer  containing  numerous  bast 
cells.  The  bast  cells  are  pearly  white  in  color  and  are  greatly  thick- 
ened, the  stratification  being  distinct  and  the  cavities  almost  obliter- 
ated. In  the  parenchyma  of  the  middle  bark  there  are  numerous 
large  stone  cells,  forming  almost  a  complete  zone  of  sclerenchyma. 
Associated  with  the  parenchyma  of  the  cortex  are  a  number  of 
secretion  cells  filled  with  a  reddish  latex,  and  the  cells  of  the  phello- 
derm  are  likewise  impregnated  with  a  similar  substance.  In  the 
Pharmacographia  Indica,  Part  VI,  page  357,  Hooper  calls  attention 
to  a  remarkable  stratum  of  stone  cells  existing  in  the  bark  of  the 
Himalayan  species,  Myrica  Nagi,  Thunb.  A  similar  layer  existing 
in  M.  asplenifolia  L.  would  indicate  that  this  was  likely  a  struc- 
tural characteristic  of  the  order,  and  would  warrant  further  investi- 
gation of  other  species. 
Chlorine  water  decomposes  so  readily  that  if  found  at  all  in  the 
stores  it  is  of  poor  quality.  Sealed  glass  tubes  containing  five 
grams  of  liquid  chlorine  are  now  to  be  had  in  commerce.  With 
one  of  these  it  is  possible  to  extemporaneously  prepare  one  kilo,  of 
chlorine  water. 
