706 
On  Sweet  Vernal  Grass  and  Golden  Oat  Grass, 
The  differences  between  the  seeds  of  the  sweet  vernal  grass 
and  the  annual  species  employed  to  adulterate  it  are  not  very 
obvious,  yet,  when  accurately  apprehended,  they  can  easily  be 
detected.  In  the  bulk,  the  seeds  of  the  true  vernal  grass  are 
darker  in  colour  than  those  of  the  other  species.  The  most 
important  characters  for  distinguishing  them  are  to  be  seen  in 
the  hairy  pales  or  barren  florets.  In  the  sweet  vernal  grass 
the  pales  are  narrowed  or  hollowed  out  in  the  middle,  so  that 
while  they  overlap  at  top  and  bottom,  they  leave  a narrow  oval 
space  in  the  middle,  through  which  the  glistening  surface  of  the 
seed  may  be  seen.  In  Antkoxanthum  Puelii  the  pales  are  quite 
straight-sided,  and  entirely  cover  the  seed.  This  difference 
may  be  seen  in  the  aspect  of  the  complete  seed  as  offered  for 
sale — Figs.  2 c and  3 c,  but  perhaps  better  in  the  drawings  of 
the  separate  glumes  of  each  species,  Figs.  2 b and  3 b.  In  the 
sweet  vernal  grass  the  enlarged  apex  of  the  pale  is  evenly  rounded, 
and  the  edge  is  uniformly  and  finely  serrate ; while  in  the  allied 
species  the  apex  has  two  or  three  irregular  teeth.  And  further, 
the  hairs  on  the  pales  of  the  sweet  vernal  grass  are  scattered 
irregularly  over  the  surface,  while  in  the  other  species  they 
are  in  lines  along  the  midrib  and  veins,  and  along  the  edges. 
Finally,  the  seeds  free  from  the  hairy  pales  of  the  sweet  vernal 
grass  are  longer  and  narrower,  and  darker  in  colour  than  those 
of  Anthoxanthum  Puelii.  In  both  the  outer  scale  is  very  large, 
completely  covering  the  seed  and  the  smaller  inner  scale.  The 
white  seed  is  of  the  same  form,  when  denuded  of  the  scales. 
The  Yellow  Oat-grass  ( Avena  flavescens,  Linn.)  Fig.  4 a,  occurs 
frequently  in  dry  meadows  and  pastures,  and  may  be  grown  in 
almost  any  kind  of  soil  or  situation.  It  produces  a considerable 
quantity  of  foliage,  and  is  a favourite  food  of  sheep.  It  is 
important  as  a late  grass  in  pastures,  and  is  therefore  a desirable 
ingredient  in  mixtures  of  seeds  used  for  laying  down  fields.  It 
has  fibrous  roots,  and  sends  out  creeping  underground  stems 
by  which  it  increases.  The  stems  of  the  oat-grass  rise  to 
a height  of  1 to  3 feet ; the  leaves  are  flat  and  somewhat  hairy, 
especially  on  the  upper  surface.  The  flowers,  which  are  very 
small  for  an  oat-grass,  are  borne  on  a branched  lax  panicle. 
The  seeds  are  enclosed  in  two  pales  ; the  outer  one  has  the  apex 
bifid  and  drawn  out  into  two  short  roughish  awns,  and  it  gives 
off  from  its  outer  surface  towards  the  apex  a long  rough-jointed 
awn.  The  inner  pale  is  white  and  membranous,  with  a bifid 
apex  ; it  is  very  obvious  in  the  seed  being  free  in  its  upper 
portion  from  the  outer  pale.  There  is  a small  crown  of  short 
white  hairs  at  the  base  of  the  pales,  and  the  longish  stalk  or 
pedicel  of  the  next  flower  has  a continuous  series  of  silvery 
hairs  along  its  sides. 
