718 
THE  TROPICAL  AGRICULTURIST. 
[May  i,  1893. 
TROPICAL  AGRICULTURE  * 
This  is  the  title  of  a volume  of  about  300  pages 
by  Dr.  H.  A.  Alford  Nicholls,  and  published  by 
Messrs.  Macmillan  & Co.  as  a “text-book”  in 
their  series  of  manuals  for  students.  The  book  is 
dedicated  by  the  author  to  Dr.  Joseph  Hooker  in 
addressing  whom  Dr.  Nicholls  says: — ‘‘If  there  is 
anything  useful  in  the  following  pages  the  credit 
is  due  in  a great  measure  to  you.”  We  are  told 
in  the  preface  that  the  idea  of  the  book  originated 
with  the  Jamaica  Government  having  offered  a 
premium  for  the  best  text-book  of  tropical  agri- 
culture specially  adapted  for  the  use  of  the  col'eges 
and  higher  schools  in  that  colony.  The  author's 
manuscripts  having  been  adjudged  the  best,  the 
same  Government  undertook  to  publish  it  after 
having  been  added  to  and  revised.  “It  is  not  a 
mere  compilation,”  says  Dr.  Nicholls,  “ but  the 
record  of  experience  that  has  been  gained  by  study, 
observation,  and  experimental  cultivations.” 
The  work  under  review  is  divided  into  two  parts  : 
Part  I Elementary  Agriculture,  and  Part  II  Agri- 
cultural Products.  The  first  part  treats  of  soils, 
their  origin,  distribution,  constituents,  classification 
and  properties;  of  the  plant  in  general,  the  func- 
tions of  its  different  organs,  fertilization,  germina 
tion,  nutrition,  and  the  different  modes  of  propa- 
gating plants  ; olimate ; manures;  rotation  of  crops; 
drainage  ; irrigation  ; tillage  operations ; pruning  ; 
budding  and  grafting. 
The  author  thus  explains  the  general  principle 
of  pruning  : 11  When  a branob  of  a tree  is  cut  off 
much  of  the  sap  or  nouiishment  that  would  have 
been  used  by  it  goes  to  the  branches  that  remain, 
and  more  especially  to  those  in  the  vicinity  of  the 
part  taken  away.  Besides  by  removing  useless 
branches,  or  as  it  is  called  ‘thinning  them  out,' 
more  air  and  light  are  allowed  to  reach  the  re- 
maining portions  of  the  plant,  and  thus  their 
assimilation  of  food  from  the  atmosphere  is  in- 
creased. The  removal  of  one  portion  of  a plant, 
whether  it  be  the  branohes,  leaves,  flowers,  or 
fruit,  is  always  followed  by  extra  development 
sooner  or  later.  If  for  instance  all  the  first  flowers 
of  young  oacao  trees  be  taken  away,  as  they  should 
be,  there  will  be  increased  fruitfulness  at  the  next 
season.  And  if  all  the  young  fruit  be  taken  off  an 
orange  tree,  flowers  will  break  out  again  and  the 
orops  will  be  reaped  at  a much  later  time."  This 
means  of  altering  the  orop  time  to  some  extent 
in  the  oase  of  fruit  trees  is,  as, the  author  remarks, 
a very  important  one  to  fruit  growers  who  will 
thus  be  enabled  to  take  advantage  of  the  fact  that 
prices  are  high  at  some  seasons  when  the  late 
crops  can  be  brought  into  the  market.  In  prun- 
ing to  increase  fruitfulness,  it  is  remarked  that 
one  has  to  observe  first  on  what  portion  of  the 
tree  or  plant  the  fruit  is  borne.  Where  it  is  borne 
by  the  wood  of  the  same  season,  it  will  be  ne- 
cessary to  prune  out  branohes  that  are  backward  in 
growth,  and  that  have  little  or  no  fresh  wood  on 
them.  Where  the  fruit  is  borne  by  the  wood  of  the 
seoond  season,  the  young  wood  must  be  out  back 
so  as  to  allow  the  strength  of  the  plant  to  be  put 
forth  in  pushing  out  flowers  instead  of  continuing 
to  inorease  the  new  wood.  LaBtly,  where  the  fruit 
is  borne  on  the  wood  of  the  stem  or  the  mature 
branohes,  the  small  branohes  and  the  young  wood 
not  required  to  inorease  the  spread  of  the  tree  must 
fall  to  the  pruning  knife. 
In  all  cases,  however,  it  is  advised,  that  suckers 
or  “ robber-Btems”  must  be  removed  from  trees 
* A Text-book  of  Tropical  Agriculture.  By  H.  A 
Alford  Nicholls,  m.d,,  f.l.s.,  &c,  With  illustrations. 
^Macmillan  & do-) 
or  bushes  grown  for  their  crops,  as  they  appro- 
priate the  Eap  or  food  neoessary  for  the  produc- 
tion of  flowers  and  fruit.  “ Pruning,”  we  are  told, 
“ does  not  simply  mean  chopping  at  a tree  with  a 
cutlass  so  as  to  deorease  its  bulk,  but  it  means 
an  important  operation  that  should  not  be  under- 
taken without  forethought,  or  without  some 
knowledge  of  its  principles.  We  are  cautioned  in 
cutting  a branch  not  to  injure  the  bark  of  the  tree 
which  will  grow  and  in  time  heal  up  the  wound. 
In  case  the  bark  is  torn  or  ragged,  a longer  time 
is  taken  for  the  work  of  repair,  and  the  wood  of 
the  tree  itself  may  become  decayed  and  there 
might  thus  be  permanent  injury.  In  order  to 
prevent  decay  by  the  aotion  of  the  air  and 
moisture,  or  by  inseots,  painting  the  wound  with 
tar  or  some  suoh  substance  is  recommended,  where 
the  branch  pruned  off  is  a large  one.  In  cutting 
away  small  shoots  it  is  advised  that  a sloping 
cut  should  be  made  coming  out  just  in  front  of 
the  bud,  forming  a wound  at  half  a rightangle 
with  the  branch.  The  reason  given  for  this  is 
that  as  soon  as  the  bud  developes,  the  increased 
vigour  of  growth  will  quiokly  heal  up  the  wound, 
while  if  any  considerable  portion  of  the  stem  is 
left  beyond  the  bud,  it  will  die  and  produce  deoay 
in  the  branch  or  cause  the  necessity  of  another 
pruning  operation  to  remove  it.  Pruners  are 
oautioned  not  to  operate  on  trees  or  shrubs  when 
they  are  lull  of  sap,  as  they  will  then  “ bleed” 
so  much  as  to  injure  the  plants.  “ The  circulation 
of  the  sap,"  says  the  author,  in  conclusion,  ‘‘is  not 
the  same  in  regard  to  time  in  all  plants  or  in 
the  same  plants  growing  in  different  plaoes  and 
in  different  olimates.  Observation  and  experiment 
are  therefore  necessary  to  determine  the  proper 
time  for  pruning,  and  a small  out  into  the  stem 
of  a plant  will  always  show  if  bleeding  is  likely 
to  take  plaoe." 
The  last  ohapter  in  the  first  part  of  the  book 
treats  of  budding  and  grafting;  and  the  various 
methods  of  grafting,  such  as  whip  or  tongue 
grafting,  wedge  grafting,  saddle  grafting,  crown 
grafting,  and  grafiiog  by  approach  are  all  fully 
explained  and  illustrated  by  means  of  diagrams. 
What  we  have  said  about  the  book  so  far  suffi- 
ciently indicates  what  the  author  was  led  to  believe, 
namely,  that  his  work  “ will  prove  serviceable  to 
paesant  proprietors,  owners  of  small  estates,  and 
intending  settlers  in  tropioal  oountnes,”  and  that 
“ it  has  supplied  a distinct  want.”  With  the  more 
practical  and  perhaps  the  more  useful  part  of  the 
book,  that  treating  of  plants  cultivated  in  the 
tropics,  we  shall  deal  in  another  issue. 
♦ 
Jamaica  at  the  World’s  Fair. — Exhibits,  con- 
sisting of  the  various  productions  of  the  island  of 
Jamaioa,  which  will  make  an  exceptionally  interest- 
ing oourt  at  Chioago,  will  leave  during  thiB  month. 
Coffee,  sugar,  rum,  and  coooa,  and  the  woods  of 
the  oolony  are  well  represented,  A guide-book  will 
be  issued  shortly,  audit  will  be  well  illustrated  by 
photogravures. — Daily  Chronicle. 
The  Java  Exhibition. — The  exhibition  of  indus- 
trial and  natural  preduots  of  the  Dutch  East  Indies, 
which  is  to  be  held  at  Batavia  in  the  course  of 
this  year  promises  to  be  a deoided  success.  The 
agricultural  seotion  will  include  extensive  exhibits 
of  oinohona,  including  flowering  branches  as  well 
as  dried  bark,  indigo  and  other  dyestuffs,  Bpices, 
gums  and  resins,  essential  oils  and  medicinal  drugs, 
of  native  as  well  as  European  use.  Prizes  are 
offered  for  the  best  treatises  on  the  cultivation  of 
and  commerce  in  oinohona,  pepper,  cubebs,  vanilla, 
cloves,  and  cinnamon,  and  for  the  best  projeot  for 
the  establishment  of  a cinchona-factory  in  Java, 
*~Elwtrml  Trades  Journal,  March  8, 
