288 
ll  is  argued  on  the  other  hand,  that  by  buying  artificial  indigo 
one  knows  exactly  that  strength  one  is  getting  but  the  reply  to  this 
argument  is  that  by  purchasing  the  natural  product  a bonus  is  ob- 
tained. 
It  is  about  eight  years  ago  that  alizarine  blue  (or  chemical  indigo) 
was  first  presented  to  the  dyeing  world  as  a superior  substitute  for 
natural  indigo,  and  althoug.h  it  possesses  good  qualities  of  its  own, 
it  has  not  yet  succeeded  in  rivalling  it.  Kach  of  the  two  qualities 
holds  its  place  in  the  textile  industry,  an  industry  which  from  year 
to  year  demands  ever  increasing  qualities  of  dye-stuffs,  and  time 
will  show  for  what  peculiar  use  each  is  best  adopted.  Up  to  to  the 
present  cloths  dyed  with  natural  indigo  have  withstood  the  effects 
of  sea  journeys  and  of  the  sun’s  rays  better  than  all  others.  It 
would  not  be  in  accordance  with  facts  to  assume  that  in  the  com- 
petition between  chemical  and  natural  indigo  a decision  has  as  yet 
been  reached  in  favour  of  or  against  one  or  other  of  the  products. 
In  Indian  planting  circles  the  opinion  is  held  that,  the  question 
will  only  be  solved  when,  under  normal  conditions,  or  at  least  more 
favourable  weather,  larger  harvests  with  improved  qualities  are 
placed  upon  the  market,  but  this  time  is  yet  to  come  and  in  the 
meantime  it  can  safely  be  taken  for  granted  that  the  natural  as 
well  as  the  chemical  indigo  will  each  find  its  field  of  usefulness  in  ^ 
the  world’s  markets. 
NITROGENOUS  PLANTS. 
It  is  now  well  kn  jwn  that  many  plants  b.-longing  to  the  natural 
order  Leguminosae  have  the  power  of  taking  in  varying  amounts 
of  atmospheric  nitrogen  and  building  this  up  into  complex  com- 
pounds within  the  plant. 
-The  cultivation  of  these  nitrogen  collectors  is  carried  on  in  many 
parts  of  Ceylon  and  different  leguminous  species  have  been  tried 
for  different  products.  Crotalaria  striata  and  others  have  been 
tried  for  tea,  Erythrina  species  (Dadap)  and  Alhizsia  moluccana 
for  cacoa  and  tea.  Mimosa  pudica,  L.,  the  sensitive  plant,  for  coco- 
nut land,  together  with  several  species  obtained  from  Europe. 
Nitrogen  and  Nematode  Nodules. 
The  formation  of  conspicuous  nodules  on  the  roots  and  rootlets 
is  the  only  indication  to  the  practical  man  that  the  plant  belongs 
to  the  Nitrogen  collecting  family,  and  as  this  is  usually  the  only 
criterion  it  is  necessary  to  clearly  state  the  characters  of  those 
nodules  which  are  nitrogenous  and  to  distinguish  them  from  those 
produced  by  nematodes  or  eel-worms.  Both  classes  of^  nodule^, 
nitrogenous  and  nematodes,  are  especially  characteristic  of  the 
same  group  of  plants,  and  it  is  quite  possible  that  the  same  species 
may  under  different  conditions  exhibit  both  kinds  of  root  growth. 
Certain  it  is  that  some  varieties  of  the  common  cultivated  bean, 
Phaseolus  vulgaris,  produce  in  Ceylon  nitrogen  nodules,  and  others 
though  growing  in  the  same  soil,  produce  nematode  swellings. 
