﻿6 
  JAS. 
  J. 
  SIMPSON 
  — 
  ENTOMOLOGICAL 
  

  

  River, 
  which 
  drains 
  the 
  country 
  to 
  the 
  east 
  of 
  the 
  Sacred 
  Lake, 
  and 
  the 
  Offin, 
  with 
  

   its 
  tributary, 
  the 
  Adra. 
  These 
  both 
  drain 
  the 
  southern 
  and 
  south-western 
  portions 
  

   of 
  Ashanti. 
  On 
  the 
  left 
  bank 
  the 
  Pra 
  River 
  is 
  joined 
  by 
  two 
  important 
  tributaries,, 
  

   the 
  Irwi 
  and 
  the 
  Birrim, 
  the 
  latter 
  of 
  which 
  is 
  much 
  the 
  larger 
  of 
  the 
  two, 
  and 
  drains 
  

   one 
  of 
  the 
  best 
  cocoa-growing 
  districts. 
  

  

  The 
  Ankobra 
  River 
  rises 
  in 
  the 
  extreme 
  northern 
  portion 
  of 
  Upper 
  Denkira, 
  close 
  

   to 
  the 
  mining 
  centre 
  of 
  Bibiani, 
  and 
  is 
  confined 
  for 
  the 
  whole 
  length 
  of 
  its 
  course 
  to 
  

   the 
  limits 
  of 
  the 
  Colony. 
  It 
  flows 
  almost 
  due 
  south 
  through 
  a 
  very 
  rich 
  mining 
  and 
  

   timber 
  country, 
  and 
  falls 
  into 
  the 
  sea 
  close 
  to 
  Axim. 
  

  

  (3.) 
  Vegetation. 
  

  

  For 
  a 
  detailed 
  study 
  of 
  the 
  vegetation 
  of 
  the 
  Gold 
  Coast 
  the 
  reader 
  should 
  consult 
  

   a 
  report* 
  by 
  Mr. 
  H. 
  N. 
  Thomson. 
  I 
  shall 
  here 
  confine 
  myself 
  to 
  a 
  few 
  notes 
  on 
  the 
  

   various 
  forest 
  areas 
  in 
  so 
  far 
  as 
  these 
  have 
  a 
  bearing 
  on 
  insect 
  distribution. 
  The 
  

   general 
  limits 
  of 
  the 
  different 
  types 
  are 
  shown 
  on 
  the 
  map 
  which 
  accompanies 
  this 
  

   report. 
  

  

  The 
  chief 
  plant 
  associations 
  in 
  the 
  Gold 
  Coast 
  are 
  as 
  follows 
  : 
  — 
  Rain 
  or 
  moist 
  

   tropical 
  evergreen 
  forests, 
  fresh- 
  water 
  swamp 
  forests, 
  monsoon 
  or 
  mixed 
  deciduous 
  

   forests, 
  savannah 
  forests, 
  and 
  pure 
  savannah. 
  

  

  The 
  tropical 
  rain 
  forests 
  contain 
  trees 
  of 
  very 
  lofty 
  growth 
  scattered 
  amongst 
  

   those 
  of 
  more 
  moderate 
  dimensions. 
  As 
  a 
  rule, 
  the 
  trees 
  in 
  the 
  rain 
  forests 
  are 
  

   connected 
  one 
  with 
  another 
  by 
  a 
  regular 
  network 
  of 
  climbers. 
  Epiphytes 
  are 
  

   crowded 
  all 
  over 
  the 
  stems 
  and 
  larger 
  branches. 
  Several 
  tiers 
  of 
  vegetation 
  corre- 
  

   sponding 
  to 
  the 
  heights 
  attained 
  by 
  the 
  component 
  species 
  are 
  to 
  be 
  met 
  with, 
  and 
  

   under 
  all 
  a 
  deep 
  gloomy 
  shade 
  prevails, 
  relieved 
  only 
  occasionally 
  by 
  spots 
  of 
  sun- 
  

   shine 
  in 
  clearings 
  formed 
  by 
  the 
  downfall 
  of 
  some 
  forest 
  giant. 
  The 
  air 
  is 
  saturated 
  

   with 
  moisture 
  and 
  is, 
  as 
  a 
  rule, 
  remarkably 
  still 
  — 
  conditions 
  very 
  favourable 
  to 
  

   luxuriant 
  forest 
  growth. 
  The 
  dry 
  season 
  is 
  of 
  short 
  duration, 
  frequently 
  interrupted 
  

   by 
  showers, 
  and 
  the 
  Harmattan 
  winds 
  are 
  feebly 
  developed. 
  This 
  type 
  of 
  forest 
  is, 
  

   in 
  its 
  typical 
  form, 
  restricted 
  on 
  the 
  coast 
  line 
  to 
  the 
  extreme 
  south-west 
  corner 
  of 
  

   the 
  Colony, 
  in 
  the 
  neighbourhood 
  of 
  Axim. 
  From 
  there 
  it 
  extends 
  northwards 
  (with 
  

   one 
  marked 
  break) 
  along 
  the 
  valleys 
  of 
  the 
  Tano 
  and 
  Ankobra 
  Rivers 
  to 
  just 
  north 
  

   of 
  the 
  7th 
  parallel. 
  An 
  extensive 
  branch 
  stretches 
  from 
  Axim 
  in 
  a 
  north-easterly 
  

   direction 
  to 
  Tarkwa. 
  This 
  is 
  the 
  type 
  found 
  in 
  the 
  greater 
  part 
  of 
  Southern 
  

   Ashanti. 
  

  

  The 
  fresh-water 
  swamp 
  forests 
  are 
  composed 
  of 
  plants 
  which 
  have 
  adapted 
  them- 
  

   selves 
  to 
  growth 
  in 
  a 
  permanently 
  wet 
  soil. 
  They 
  have 
  much 
  the 
  appearance 
  of 
  

   plants 
  inhabiting 
  the 
  rain 
  forests, 
  but 
  are 
  not 
  so 
  crowded, 
  the 
  formation 
  being 
  a 
  

   comparatively 
  open 
  one. 
  The 
  swamps 
  occur 
  chiefly 
  in 
  the 
  vicinity 
  of 
  the 
  larger 
  

   rivers, 
  and 
  are 
  often 
  caused 
  by 
  their 
  overflow 
  ; 
  they 
  occur 
  also 
  in 
  hilly 
  country 
  

   along 
  some 
  of 
  the 
  deeper 
  valleys. 
  

  

  The 
  monsoon 
  or 
  mixed 
  deciduous 
  forests 
  are 
  very 
  rich 
  in 
  plants 
  of 
  economic 
  

   importance. 
  They 
  are 
  inhabited 
  by 
  both 
  tropophilous 
  and 
  hygrophilous 
  plants 
  in 
  

  

  * 
  Colonial 
  Reports: 
  Miscellaneous 
  Col. 
  4993 
  Gold 
  Coast: 
  Report 
  on 
  Forests 
  1910. 
  

  

  