June  1,  1897.]  Supplement  to  the  “ Tropical  Agriculturist^ 
885 
Agriculture.  It  must,  however,  be  encouraging  to 
those  who  are  imin."(iiately  concerned  in  tlie  wel- 
fare of  this  useful  institution,  to  know  that  we 
have  a wise,  shrewd  and  far-seeing  ruler,  who  will 
not  be  easily  led  away  by  the  crude  ideas  of  others. 
H.E.  the  Governor,  however,  does  not  yet  appear 
to  have  been  informed  cf  all  that  has  been  done  by 
the  Agricultural  School.  In  his  speech  at  the  late 
Agri- Horticultural  Show  at  Nuwara  Eliya,  His 
E.vcellency  alluded  to  the  School  of  Agriculture, 
and  we  were  told  that  a Commission  had  been  ap- 
pointed to  inquire  whether  the  School  should  be 
“ ended  or  mended.”  It  is  also  satisfactory  to  find 
that  His  E.vcellency  is  convinced  that  some  system 
of  Agricultural  education  is  necessary  fur  this 
island,  and  such  a system,  he  hopes,  will  be  de- 
vised by  the  Commission. 
I do  not  say  that  the  Agricultural  School  has  so 
far  been  altogether  a success.  There  are  many 
useful  things  which  it  might  have  done,  and  upon 
which  I mean  to  comment  later  on.  But  it  is  at 
the  same  time  incorrect  and  unfair  to  say 
that  the  School  has  altogether  been  a failure. 
It  will  then  be  of  interest  to  inquire  at  this  stage 
what  the  School  has  done  so  far,  and  to  what  ev- 
tent  it  has  been  of  benefit  to  this  island. 
We  will  begin  with  coconuts,  as  this  product 
was  prominently  referred  to  in  the  Legislative 
Council  by  the  Hon.  the  Tamil  Member  stating 
that  the  Ag'-icultural  students  had  not  been 
taught  how  to  plant  them,  It  will  be  of  interest 
to  those  coiicerned  to  learn  that  a very  useful 
pamphlet  on  coconut  plantation  has  been  c mpiled 
in  Sinhalese,  and  published  some  years  ago  by  a 
student  of  the  Colombo  School  of  Agriculture. 
This  pamphlet  fully  deals  with  the  subject.  I 
know  personally  that  many  a native  planter  has 
been  greatly  benefited  by  this  little  work.  The 
Sinhalese  press  spoke  very  highly  in  its  favour. 
The  improved  system  of  coconut  cultivation  at 
present  noticeable  in  some  parts  of  the  island,  es- 
pecially in  native  gardens,  is,  I make  bold  to  say, 
in  a great  measure  the  due  to  influence  of  the 
School  cf  Agriculuire.  An  alarm  was  raised 
in  some  quarters  of  the  islandsome  time  ago 
that  the  coconut  palm  was  attacked  by  a serious 
leaf  disease  which  threatened  to  destroy  it  al- 
together. The  School  of  Agriculture  promptly 
came  to  the  front  on  this  occasion,  and  by 
careful  investigtion  and  publication  of  much 
useful  information  on  the  subject,  soon  dispelled 
all  fear  of  any  such  possible  calamity  and  gave  an 
impetus  to  more  liberal  cultivation.  One  of  the 
oldest  and  most  exper  ienced  journalists  of  the  day 
then  wrote  a leader  on  the  “ Progress  of  Ag  icul- 
ture,”  in  which  he  highly  complimented  Mr.  Green, 
the  founder  of  the  School  of  Agriculture. 
“TRAVELLER.” 
♦ 
INSECT  PESTS. 
(Continued  ). 
Insects  are  remarkable  for  the  fecundity  of  each 
species  as  well  as  for  the  great  number  of  species. 
If  all  the  progeny  from  a single  pair  of  almost  any 
species  of  insect  w’ere  allowed  to  survive  long 
enough  to  procreate,  but  very  few  years  would 
elapse  in  a land  before  that  particular  species 
would  quite  exterminate  itself  with  all  that  it  fed 
upon,  so  immensely  superabundant  would  it  have 
become.  The  myriads  upon  myriads  of  locu.sts 
which  overrun  this  country  are  known  to  all,  and 
yet  these  locusts  connot  be  called  remarkably 
prolific  insects.  The  number  of  eggs  they  lay  is 
small  compared  to  the  number  laid  by  many  other 
in.sects;  at  the  most  it  is  not  over  one  hundred  and 
fifty.  The  number  of  individuals  which  might 
arise  from  one  aphis  during  the  course  of  a single 
season  is  almost  incaculable.  It  amounts  to 
billions  of  billions,  numbers  entirely  beyond 
human  comprehension.  If,  according  to  Dr.  J.  A. 
Lintner,  in  speaking  of  the  Hop  Aphis  (Fhorodon 
humili),  every  individual  should  attain  maturity 
and  produce  its  full  complement  of  young  {’which, 
however,  can  happily  never  occur  in  nature),  we 
should  have  as  the  number  in  the  twelfth  brood 
alone,  disregarding  those  of  all  the  preceding 
broods  (thirteen  broods  in  one  season  have  been 
observed)  no  less  than  10,000,000,000,000,000,000, 
000  (ten  sextillions)  of  individuals.  Eigures  in  a 
case  like  this  fail  to  convey  any  adequate 
conception. 
The  writer  quoted,  to  impress  the  enormity  of 
the  number,  makes  the  following  computation, 
using  space  and  the  velocity  of  light,  which  is 
about  eleven  and  one-fifth  million  miles  per 
minute  as  his  measures:  “ Were  the  brood 
marshalled  in  line  with  ten  individuals  to  the 
linear  inch  touching  one  another,  the  procession 
would  extend  to  the  sun  (a  space  which  light 
traverses  in  eight  minutes)  and  beyond  it  to  the 
nearest  fixed  star  (traversed  by  light  only  in  six 
years)  and  still  onward  in  space  beyond  the  most 
distant  star  that  the  strongest  telescope  may  bring 
to  our  view,  to  a point  so  inconceivably  remote 
that  the  light  could  only  reach  us  from  it  in 
twenty-five  hundred  years  ! ” 
Aphides  are  small  insects  and  an  individual 
inflicts  but  an  infinitely  small  drain  on  the 
sap  of  a plant.  But  when  this  drain  is  magni- 
fied a million  times,  the  loss  to  the  plant  is 
sadly  apparent.  The  number  of  aphides  infesting 
a certain  cherry  tree,  ten  feet  in  height,  was 
once  estimated  to  be  twelve  millions,  or  more 
than  seven  times  the  total  population  of  Cape 
Colony.  The  number  which  are  often  seen  con- 
gregated on  a single  head  of  cabbage  must  be 
over  one  hundred  thousand. 
Voracity  and  Destructiveness  of  Insects. 
Not  alone  are  in.sects  remarkable  for  their 
incalculable  numbers,  but  for  their  extraordinary 
voracity  and  rapid  growth  as  well.  Mr.  L 
Trouvelot,  a French  naturalist,  in  studying' one 
of  the  silk  worms  (Telea  polyphemus,Cmm.)  found 
that  the  larva  when  full  grown  weighed  four 
thousand  one  hundred  and  forty  times  as  much 
as  it  did  when  hatched  from  the  egg ; and  that 
during  its  growth  it  had  consumed  food  to  the 
amount  of  eighty-six  thousand  times  its  original 
weight.  If  a man  grew  in  a similar  proportion 
he  would  weigh  twelve  tons  and  consume  two 
hundred  and  fifty  tons  of  food.  Another  writer 
mentions  a flesh-feeding  larva  which  comsumed 
two  hundred  times  its  weight  in  one  day,  and 
a certain  caterpillar  which  increased  in  weight 
ten  thousand  times  in  thirty  days.  The  losses 
incurred  through  the  ravages  of  insects  ar^ 
