144 
Supplement  to  the  ^‘Tropical  Agriculmrist”  [Aug-  1,  1895. 
AN  IMPORTANT  LETTER  ABOUT  RHEA. 
Tlie  Af/riciiltural  (razette  of  N.S.  Wales  for 
April  Iasi  piiblislies  a letter  from  Mr.  W.  Leedliara 
(Jrowe,  of  10,  Jeffrey's  Street,  St.  Mary  A.\e, 
Loiulon,  wliicli  contains  some  valuable  information 
about  Rliea  from  a practical  source.  The  fol- 
lowing is  taken  from  it “ For  many  years  1 have 
been  greatly  interested  in  tlie  properties  and  pos- 
sibilities of  this  fibre,  and  have  examined  many 
processes,  more  or  less  successful,  for  treating  it. 
Twelve  years  ago  I presided  over  a meeting  in 
London  of  merchants  and  brokers,  on  which 
occasion  fabrics  of  every  description  were  exhibited, 
made  from  pure  Rhea,  and  from  Rhea  mixed  with 
wool  or  other  fibres.  It  was  there  demonstrated 
by  tests  that  in  the  case  of  fire-hose  Rhea  had 
something  like  three  times  the  existing  power 
to  moisture  of  flax.  These  fabrics  were  all  made  in 
Augouleme  from  Rhea  grown  in  Algeria,  and  treat- 
ed, 1 believe,  by  the  Favier-Renny  process.  The 
(juantity  grown  there,  however,  is  small,  and  not 
of  the  best  quality.  I have  been  interested  in 
growing  Rhea  in  Joliore,  and  in  its  importation 
from  Cliina  and  other  places. 
“ In  India  it  cannot  be  grown  successfully  to  pay. 
Undoubtedly  in  N.S.  Wales  and  Queensland  there 
are  districts  where  it  could  be  cultivated  lo  advant- 
age. The  two  main  difficulties  are,  however,  its 
decortication  and  the  insuring  a regular  supply  at 
a sufficiently  low  price.  Where  I differ  from  your 
article  is  the  necessity  for  a machine  to  decorticate 
the  stems.  I am  convinced  that  the  cost  and  ex- 
pense of  working  machinery  would  be  too  great  for 
tlie  value  of  the  fibre.  Some  very  efficient 
machines  for  this  purpose  have  been  produced, 
those  of  Messrs.  Death  v'c  Ellwood  among  others, 
and  which  were  tried  in  Johore,  but  abandoned. 
The  simplest  method  of  decortication  appears  to 
be  the  Favier  process— of  subjecting  the  cane  to 
steam  in  chests  for  about  20  minutes,  when  the 
covering  can  be  removed  by  hand, and  theribbonleft 
free.  Hitherto  it  has  been  decorticated,  brought 
to  this  country  in  ribbons,  and  then  treated 
chemically  to  remove  the  gum,  but  the  carriage 
upon  riVibons  is  very  heavy,  and  the  entire  process 
should  be  carried  out  upon  the  spot  where  it  is 
grown.  Many  processes  have  been  patented  for 
treating  the  ribbons,  but  the  most  successful 
appear  to  be  the  simplest — a treatment  with  soda 
and  hot  water.  If  Rhea  fibre  in  merchantable 
condition  can  be  produced  in  quantity  and  laid 
down  in  London  at  a moderate  price,  it  has  an 
immense  future.  A numbe.-  of  syndicates  and  small 
quantities  have  .at  various  times  been  formed  here 
to  work  special  methods  of  treating  the  fibre.  All 
have  failed,  and  why?  First,  for  want  of  a re- 
gular supply ; secondly,  because  the  cost  of  the 
ffbre  when  prepared  was  exce.ssive.  Our  mauu- 
factiirers  are  ready  to  buy  and  use  Rhea,  and 
anxious  to  get  it,  but  must  have  a continuous 
supply  ensured.  They  will  not  otherwi.se  alter 
their  machinery,  or  introduce  a new  fibre  to  the 
market.  Rhea  must  largely  compete  with  cotton, 
which  is  now  very  low,  but  il  the  tinished  fibre, 
which  jiacks  closely,  were  sent  home,  it  might  do 
this  successfully.  I have  at  variotus  time.s  imported 
the  Khea  ribbons  from  China  at  a cost,  of  seldom 
much  under  D-JO  per  ton  .lelivered  here,  but 
such  a price  is  prohibitory.  It  a small  regulai 
supply  were  ensured  to  commence  with,  and  the 
practical  use  of  the  fibre  e.stablished,  a stimulus 
would  be  given  to  production,  but  until  that  takes 
})lace,  Rhea  will  remain  the  Will-o’-the-Wisp  of 
sanguine  speculators.  ” 
CONTAGIOUS  DISEASES  OF  INSECTS. 
In.sects  have  long  been  known  to  be  subject 
to  contagious  diseases.  This  knowledge,  how- 
ever, has  not  been  widespread,  and  com- 
paratively few  have  considered  it  in  its  bearings 
on  practical  agriculture.  That  it  has  important 
bearings  in  this  direction  no  one  can  doubt 
who  has  ob.served  the  progress  of  an  epidemic 
amongst  insects.  None  of  the  plagues  recorded 
in  history  has  ever  carried  such  destruction  in 
its  path  as  to  be  compared  with  the  havoc  w'rought 
by  some  of  the  common  insect  diseases. 
The  earlie.st  known  of  insect  epidemics  was 
the  disease  known  as  muscnrdine,  affecting  most 
seriously  the  cultivated  silkworm  in  France  and 
Italy.  This  disease  was  easily  recognised  by  the 
fact  that  the  dead  worm  became  in  a short  time 
covered  with  a whitish  powder.  Between  thirty 
and  forty  years  ago  another  still  more  serious 
disease  was  recognised  in  tbe.se  countries  and 
cUled  pebrine-.  This  disea.se  at  one  time  threat- 
ened the  very  existence  of  the  silk  industry  of 
European  countries.  Still  a third  disease  of  the 
silkworm,  the  flacherie,  rivalling  even  pkbrine  in 
its  destructive  power,  was  first  discovered  and 
carefully  studied  by  the  renowned  M.  Pasteur. 
The  disease  of  the  bee  known  as  foul  brood  was 
recognised  as  a contagious  disease  fully  twenty- 
five  years  ago,  and  has  claimed,  and  still  claims, 
the  attention  of  beekeepers  on  account  of  the 
enormous  losses  it  has  cost.  Another,  quite  ns 
important  as  the  diseases  just  mentioned,  and 
one  full  of  suggestiveness,  is  the  disea.se  attack- 
ing the  chinch  bug  of  the  eastern  United  States. 
This  disease  has  been  known  for  more  than 
a quarter  of  a century,  but  never  carefully 
studied  till  during  the  last  ten  years.  Who  has 
not  heard  of  the  wonderful  effects  obtained  by 
spreading  the  disease  in  Kansas,  an  effect  as 
striking  as  the  work  of  our  Vedalia  cardinnlix. 
Every  one  has  probably  noticed  some  examples 
of  these  contagious  disease.s,  even  if  not  recog- 
nizing their  nature.  The  common  house  flies 
often  seen  dead  and  sticking  fast  about  the 
window,  and  surrounded  by  a whitish  halo,  is 
a common  form.  Scale  in.sects,  especially 
lecaniuim,  covered  and  almost  hidden  by  a whitish 
powdery  substance,  are  commonly  to  be  seen. 
Plant  lice  are  not  uncommonly  found  sticking 
to  the  plant,  dead  and  discoloured  and  looking 
much  as  though  killed  by  kero.sene  emusion,  but 
when  no  treatment  had  been  made.  Caterpillars 
may  often  be  found  hanging  by  one  leg  to  the 
plant  and  the  whole  body  soft  and  rotten,  or 
dried,  stiff  and  shrivelled.  In  some  one  or  another 
of  tln^se  forms  we  have  iiuite  likely  become 
ac<iuainf(Hl  with  a few  of  the  diseases  of  insects, 
but  it  is  doubtful  if  any  of  us  has  a proper  idea  of 
their  extent  and  prevalence. 
These  disea.ses  are  all  due  to  the  multiplication 
within  the  body  of  certain  specific  organisms, 
certain  germs.  An  epidemic  may  be  due  to  one 
kind  alone  or  may  be  a number  of  diseases 
altackitig  the  insect  together.  Three  different 
kinds  of  organisms  are  known  to  produce  diseases 
among  insects, 
