TALL  TREES  IN  AUSTRALIA. 
51 
of  our  timber  trees,  in  the  rich  diluvial  deposits  of  sheltered 
depressions  within  Victorian  ranges,  finds  its  principal  explana- 
tion, perhaps,  in  the  circumstance,  that  the  richness  of  the  soil  is 
combined  with  a  humid  geniality  of  the  climate,  never  sinking  to 
the  colder  temperature  of  Tasmania,  nor  rising  to  a  warmth  less 
favorable  to  the  strong  development  of  these  trees  in  New  South 
Wales,  nor  ever  reduced  to  that  comparative  dryness  of  air 
which,  even  to  some  extent  in  the  mountain-ravines  of  South 
Australia,  is  experienced.  The  absence  of  living  gigantic  forms 
of  animal  life  amidst  these,  the  hugest  forms  of  the  vegetable 
world,  is  all  the  more  striking. 
"  Statistics  of  actual  measurement  of  trees,  compiled  in  various 
parts  of  the  globe,  would  be  replete  with  deep  interest,  not  merely 
to  science,  but  disclose,  also,  in  copious  instances,  magnitudes  of 
resources  but  little  understood  up  to  the  present  day.  Not 
merely,  however,  in  their  stupendous  altitude,  but  also  in  their 
celerity  of  growth,  we  have,  in  all  probability,  to  accede  to  Aus- 
tralian trees  the  prize.  Extensive  comparisons,  instituted  in  the 
Botanic  Gardens  of  this  metropolis,  prove  several  species  of  Eu- 
calyptus, more  particularly  Eucalyptus  globulus  and  Eucalyptus 
obliqua,  as  well  as  certain  Acacias — for  instance,  Acacia  decur- 
rens,  or  Acacia  mollissima — far  excelling,  in  their  ratio  of  devel- 
opment, any  extra- Australian  trees,  even  on  dry  and  exposed 
spots,  such  into  which  spontaneously  our  blue  gum-trees  would 
not  penetrate.  This  marvellous  quickness  of  growth,  combined 
with  a  perfect  fitness  to  resist  drought,  has  rendered  many  of 
our  trees  famed  abroad,  especially  so  in  countries  where  the  sup- 
ply of  fuel  or  of  hard- woods  is  not  readily  attainable,  or  where 
for  raising  shelter,  like  around  the  cinchona-plantations  of  India, 
the  early  and  copious  command  of  tall  vegetation  is  of  impera- 
tive importance.  To  us  here  this  ought  to  be  a  subject  of  mani- 
fold significance.  I  scarcely  need  refer  to  the  fact,  that,  for 
numerous  unemployed  persons,  the  gathering  of  Eucalyptus 
seeds,  of  which  a  pound  weight  suffices  to  raise  many  thousand 
trees,  might  be  a  source  of  lucrative  and  extensive  employment  ; 
but  on  this  I  wish  to  dwell,  that  in  Australian  vegetation  we 
probably  possess  the  means  of  obliterating  the  rainless  zones  of 
the  globe,  to  spread  at  last  woods  over  our  deserts,  and  thereby 
