364 
Reviews. 
Am.  Jour.  Pharm 
July,  1894. 
with  certainty  from  Florida  where  first  collected  and  described  by  Dr.  Chap- 
man. In  the  Missouri  locality  it  was  found  in  swamp  lands  which  appear  to  be 
always  under  water  and  associated  with  plants  known  to  be  of  a  distinctly 
southern  range.  This  discovery  has  suggested  and  supplied  the  material  for  the 
present  valuable  contribution. 
The  plant  appears  to  propagate  largely  by  sending  out  suckers  which  may 
account  for  the  large  preponderance  of  plants  of  one  sex  in  each  swamp.  The 
habit  appears  to  be  arborescent  rather  than  shrubby. 
The  tree  is  dioecious,  and  the  flowers  appear  in  the  early  spring,  before  the 
leaves,  from  buds  developed  during  the  preceding  autumn.  The  staminate 
flowers  are  devoid  of  any  perianth,  and  are  in  catkins  1  to  7  inches  long.  The 
pistillate  ones  are  in  short  catkin-like  clusters,  %  in.  long,  and  possess  a  rudi- 
mentary perianth  of  a  few  small  glandular  fringed  scales.  The  character  of  both 
anther  and  stigma  bespeak  wind  pollination.  The  leaves  are  lanceolate  to 
eiliptical-lanceolate  acute  at  both  ends,  narrowly  revolute  and  petiolate. 
Stipules  could  not  be  seen  nor  even  stipular  scars  discovered.  One  of  the 
remarkable  characters,  is  the  exceeding  lightness  of  the  wood.  That  of  the 
stem  showing  a  density  of  0*207,  an(i  of  the  root  0*151  water  being  unity,  being 
lighter  than  the  bark  of  Quercus  suder,  the  density  of  which  is  0*240,  and 
which  has  been  considered  lighter  than  any  wood  of  which  a  record  can  be 
found.  The  figures  given  for  other  light  woods  are  0 chroma  lagopus,  0*240, 
the  East  Indian  "  Dedoaf  Tha  "  0*260,  and  for  indigenous  trees  the  Ficus  aurea 
of  Florida,  0*2616,  Tupelo  (Nyssa)  0*519,  white  cedar  0*332,  and  the  willows 
and  poplars  ranging  between  0*363  and  0*607.  The  extreme  lightness  of  the 
wood  of  Leitneria  is  due  to  its  loose  structure  and  softness  of  its  tissues,  which 
are  easily  compressible  under  the  thumb-nail,  and  the  absence  of  any  heart 
wood. 
A  careful  microscopic  examination  was  made,  and  the  anatomy  is  described 
in  detail.  The  stem  is  peculiar  for  the  presence  of  secretion  passages  accom- 
panying the  pith  sheath.  The  entire  absence  of  these  secretion  reservoirs,  and 
of  sieve-tubes  and  grit  cells  in  the  cortex  is  noteworthy.  The  medullary  rays 
are  usually  only  one  or  two  cells  in  thickness.  The  periodic  growth  rings  are 
evident  only  on  examining  the  wood  with  a  lens.  The  most  striking  feature 
of  these  rings  is  the  production  of  a  row  of  wood  parenchyma  cells  replacing 
the  libriform  in  the  first  series  cut-off  by  the  cambium,  each  spring  in  the 
beginning  of  the  year's  growth.  The  cortex  is  rich  in  tannin,  likewise  the 
epidermis  of  the  leaf.  The  leaf  structure  shows  immediately  under  the  upper 
epidermis  a  layer  of  quadrate  cells,  each  containing  a  large  stellate  crystal. 
The  mesophyll  is  composed  of  2  or  3  layers  of  compactly  placed,  rather  short 
palisade  cells  and  a  spongy  parenchyma  with  ample  intercellular  spaces  below. 
The  pubescence  is  of  two  kinds — slender-pointed,  thick-walled,  occasionally 
binate  hairs,  usually  with  transverse  septa  especially  toward  the  widened  base, 
and  less  numerous  clavate  hairs  septate  both  longitudinally  and  transversely, 
their  small  cells  with  yellow  contents.  The  habit,  morphology  and  histology 
of  the  plant  are  handsomely  illustrated  by  15  full-page  plates,  8  of  which  are 
photomicrographs. 
The  views  of  the  various  systematists  are  explained.  Bentham  and  Hooker 
considered  this  to  be  a  monotypic  genus,  and  entitled  to  ordinal  rank  under  the 
name  Leitnerice,  which  decision  is  sustained  by  Engler  (Engler  and  Prantl. 
