﻿RESEARCH 
  ON 
  THE 
  GOLD 
  COAST. 
  7 
  

  

  varying 
  proportions 
  according 
  to 
  local 
  variations 
  in 
  the 
  rainfall 
  and 
  soil. 
  Owing 
  to 
  

   the 
  complete 
  or 
  nearly 
  complete 
  defoliation 
  of 
  the 
  tropophilous 
  plants 
  during 
  the 
  

   dry 
  season 
  this 
  form 
  is 
  easily 
  distinguished 
  from 
  the 
  rain 
  and 
  evergreen 
  forests. 
  

   This 
  type 
  is 
  found 
  in 
  isolated 
  belts 
  in 
  the 
  Gold 
  Coast. 
  

  

  The 
  transition 
  between 
  the 
  rain 
  forest 
  and 
  the 
  savannah 
  forest 
  is, 
  on 
  the 
  whole, 
  

   abrupt. 
  This 
  is 
  accounted 
  for 
  by 
  the 
  fact 
  that 
  in 
  the 
  Gold 
  Coast 
  and 
  Southern 
  

   Nigeria 
  the 
  so-called 
  dry 
  season 
  is 
  tempered 
  by 
  frequent 
  showers 
  during 
  the 
  tornado 
  

   months, 
  which 
  coincide 
  with 
  the 
  vegetative 
  periods 
  of 
  the 
  grasses, 
  and 
  thus 
  favours 
  

   them 
  at 
  the 
  expense 
  of 
  forest 
  growth. 
  In 
  other 
  words, 
  owing 
  to 
  this 
  feature 
  of 
  the 
  

   climate, 
  as 
  soon 
  as 
  an 
  area 
  becomes, 
  from 
  the 
  reduction 
  in 
  the 
  annual 
  rainfall, 
  unsuit- 
  

   able 
  for 
  luxuriant 
  forest 
  growth 
  it 
  is 
  appropriated 
  by 
  the 
  grasses 
  instead 
  of 
  by 
  the 
  

   intermediate 
  stage 
  represented 
  by 
  the 
  typical 
  monsoon 
  forests. 
  

  

  The 
  savannah 
  forests 
  constitute 
  a 
  park-like 
  formation, 
  rich 
  in 
  terrestrial 
  herbs 
  and 
  

   more 
  particularly 
  in 
  grasses. 
  The 
  tree 
  growth 
  is 
  represented 
  by 
  arboreal 
  tropo- 
  

   phytes 
  and 
  evergreen 
  xerophytes, 
  but 
  the 
  latter 
  are 
  not 
  numerous, 
  and 
  form 
  an 
  

   insignificant 
  proportion 
  of 
  the 
  vegetation. 
  . 
  The 
  density 
  of 
  the 
  stock, 
  so 
  far 
  as 
  trees 
  are 
  

   concerned, 
  varies 
  in 
  accordance 
  with 
  the 
  nature 
  of 
  the 
  soil 
  and 
  its 
  telluric 
  moisture. 
  

   This 
  type 
  of 
  forest, 
  together 
  with 
  patches 
  of 
  scrub 
  forest, 
  are 
  well 
  represented 
  on 
  the 
  

   south-east 
  sea-board, 
  whence 
  they 
  extend 
  in 
  a 
  gradually 
  narrowing 
  belt 
  as 
  far 
  west 
  

   .as 
  Sekondi. 
  To 
  the 
  north 
  of 
  Accra 
  they 
  follow 
  the 
  plain, 
  and 
  occupy 
  the 
  country 
  

   up 
  to 
  the 
  foot 
  of 
  the 
  hills 
  ; 
  then, 
  sweeping 
  round 
  to 
  the 
  north, 
  they 
  follow 
  the 
  

   valley 
  of 
  the 
  Volta 
  River 
  and 
  gradually 
  broaden 
  out 
  till, 
  approximately 
  at 
  latitude 
  6° 
  

   30' 
  N., 
  they 
  rapidly 
  increase 
  in 
  area, 
  and, 
  bending 
  away 
  to 
  the 
  north-east, 
  occupy 
  

   the 
  northern 
  half 
  of 
  Ashanti 
  (from 
  east 
  to 
  west) 
  right 
  up 
  to 
  the 
  Volta 
  River 
  and 
  

   practically 
  the 
  whole 
  of 
  the 
  Northern 
  Territories 
  on 
  the 
  opposite 
  bank. 
  

  

  Savannahs 
  consist 
  of 
  formations 
  in 
  which 
  trees 
  are 
  practically 
  absent, 
  and 
  the 
  

   dominant 
  growth 
  is 
  represented 
  by 
  the 
  grasses. 
  They 
  occur 
  here 
  and 
  there 
  among 
  

   the 
  savannah 
  forests, 
  and 
  are 
  not 
  extensive. 
  

  

  Thorn 
  forests 
  are 
  also 
  poorly 
  represented, 
  and 
  occur 
  only 
  in 
  small 
  patches, 
  such 
  as 
  

   near 
  Accra, 
  and 
  again 
  in 
  the 
  Banda 
  country 
  of 
  north-western 
  Ashanti, 
  within 
  the 
  

   savannah 
  forest 
  districts. 
  

  

  I 
  hope 
  to 
  show 
  later 
  on 
  that 
  these 
  forest 
  formations 
  are 
  intimately 
  associated 
  with 
  

   the 
  distribution 
  of 
  the 
  various 
  species 
  of 
  Glossina. 
  Reference 
  to 
  the 
  map 
  will 
  show 
  

   this 
  to 
  a 
  certain 
  extent. 
  

  

  2. 
  Climate 
  and 
  Rainfall.* 
  

  

  As 
  has 
  been 
  shown 
  at 
  considerable 
  length 
  in 
  previous 
  reports, 
  temperature, 
  

   humidity, 
  and 
  the 
  length 
  of 
  the 
  wet 
  and 
  dry 
  seasons 
  respectively 
  have 
  a 
  distinct 
  

   bearing 
  on 
  the 
  distribution 
  of 
  the 
  insect 
  fauna, 
  so 
  that 
  the 
  following 
  brief 
  notes 
  and 
  

   tables 
  have 
  been 
  prepared 
  to 
  show 
  the 
  main 
  characteristics 
  of 
  the 
  various 
  regions. 
  

  

  * 
  For 
  a 
  more 
  detailed 
  study 
  of 
  this 
  subject 
  see 
  Report 
  on 
  Southern 
  Nigeria 
  in 
  this 
  

   Bulletin, 
  Vol. 
  iii, 
  pp 
  145-155, 
  

  

  