﻿50 
  DR. 
  A. 
  INGRAM. 
  

  

  In 
  many 
  of 
  the 
  trees 
  in 
  the 
  neighbourhood 
  of 
  European 
  quarters 
  and 
  Rest 
  

   Houses 
  " 
  rot 
  " 
  holes 
  were 
  found 
  ; 
  with 
  the 
  exception 
  of 
  three, 
  which 
  contained 
  

   water 
  and 
  mosquito 
  larvae, 
  these 
  holes 
  were 
  either 
  absolutely 
  dry 
  or 
  showed 
  very 
  

   slight 
  moisture, 
  but 
  as 
  many 
  of 
  them 
  proved 
  capable 
  of 
  holding 
  water, 
  this 
  dryness 
  

   was 
  probably 
  due 
  to 
  the 
  dearth 
  of 
  rain. 
  The 
  debris 
  collected 
  in 
  25 
  of 
  these 
  holes 
  

   was 
  scraped 
  out 
  and, 
  after 
  thorough 
  drying 
  in 
  the 
  shade 
  where 
  there 
  was 
  any 
  

   indication 
  of 
  moisture, 
  was 
  preserved 
  with 
  a 
  view 
  to 
  testing 
  it 
  for 
  the 
  presence 
  of 
  

   " 
  resistant 
  ' 
  eggs. 
  Twelve 
  of 
  these 
  samples 
  were 
  experimented 
  with 
  whilst 
  the 
  

   tour 
  was 
  in 
  progress, 
  but 
  in 
  no 
  instance 
  did 
  any 
  mosquito 
  larvae 
  hatch. 
  As 
  it 
  

   was 
  thought 
  that 
  the 
  conditions 
  obtaining 
  " 
  en 
  route 
  " 
  were 
  not 
  ideal 
  for 
  the 
  hatching 
  

   of 
  larvae, 
  the 
  remaining 
  samples 
  were 
  brought 
  back 
  to 
  Accra, 
  where 
  after 
  being 
  

   immersed 
  in 
  water 
  they 
  were 
  kept 
  under 
  observation 
  for 
  a 
  period 
  of 
  one 
  month 
  

   without 
  appearance 
  of 
  larvae. 
  It 
  seems 
  open 
  to 
  doubt 
  whether 
  Stegomyia 
  fasciata 
  

   and 
  other 
  species 
  of 
  this 
  genus 
  tide 
  over 
  the 
  dry 
  season 
  in 
  the 
  Northern 
  Territories 
  

   by 
  means 
  of 
  " 
  resistant 
  " 
  eggs 
  stranded 
  in 
  " 
  rot 
  " 
  holes 
  of 
  trees. 
  

  

  Portions 
  of 
  the 
  leaves 
  and 
  twigs 
  of 
  those 
  trees 
  near 
  the 
  dwellings 
  which 
  seemed 
  

   to 
  show 
  " 
  rot 
  " 
  holes 
  most 
  commonly 
  were 
  collected 
  for 
  identification 
  purposes 
  

   and 
  were 
  forwarded 
  to 
  the 
  Director 
  of 
  Agriculture 
  at 
  Aburi. 
  Poinciana 
  regia, 
  the 
  

   flamboyant 
  (often 
  planted 
  for 
  ornament 
  near 
  European 
  houses), 
  wild 
  fig 
  trees, 
  

   mangoes, 
  silk-cotton 
  trees, 
  " 
  dawa-dawa 
  ' 
  trees 
  (Parkia 
  biglobosa) 
  and 
  tamarinds 
  

   were 
  frequent 
  offenders 
  in 
  this 
  respect. 
  

  

  With 
  regard 
  to 
  the 
  above-mentioned 
  specimens 
  of 
  trees 
  the 
  Senior 
  Curator 
  of 
  the 
  

   garden 
  at 
  Tamale, 
  to 
  whom 
  they 
  were 
  submitted 
  for 
  identification 
  by 
  the 
  Director 
  

   of 
  Agriculture, 
  writes 
  under 
  date 
  23.xii.1918 
  as 
  follows: 
  — 
  ■" 
  Specimens 
  received; 
  

   I 
  will 
  do 
  all 
  I 
  can 
  to 
  obtain 
  full 
  botanic 
  names, 
  but 
  it 
  will 
  take 
  some 
  time. 
  Most 
  

   of 
  the 
  trees 
  grow 
  in 
  districts 
  remote 
  from 
  Tamale. 
  ... 
  As 
  regards 
  the 
  point 
  raised 
  

   by 
  Dr. 
  Ingram 
  about 
  these 
  trees 
  developing 
  " 
  rot 
  " 
  holes, 
  (this) 
  might 
  be 
  applied 
  

   to 
  any 
  tree 
  growing 
  in 
  the 
  Northern 
  Territories 
  large 
  enough 
  to 
  afford 
  firewood. 
  

   Live 
  branches 
  are 
  hacked 
  off 
  to 
  be 
  dried 
  for 
  firewood, 
  causing 
  jagged 
  wounds 
  which 
  

   soon 
  develop 
  into 
  " 
  rot 
  " 
  holes 
  ; 
  rather 
  the 
  treatment 
  than 
  the 
  tree." 
  The 
  trees, 
  

   however, 
  from 
  which 
  the 
  specimens 
  in 
  question 
  were 
  obtained 
  were 
  those 
  growing 
  

   close 
  to 
  the 
  quarters 
  of 
  the 
  European 
  officials 
  in 
  the 
  stations 
  or 
  those 
  in 
  the 
  com- 
  

   pounds 
  of 
  the 
  European 
  Rest 
  Houses 
  ; 
  such 
  trees 
  are 
  not 
  usually 
  made 
  use 
  of 
  for 
  

   firewood 
  by 
  the 
  natives, 
  but 
  are 
  carefully 
  preserved 
  for 
  shade 
  or 
  for 
  ornamental 
  

   purposes. 
  

  

  The 
  compounds 
  of 
  44 
  villages 
  and 
  towns 
  in 
  the 
  Northern 
  Territories 
  were 
  visited 
  

   and 
  samples 
  of 
  mosquito 
  larvae 
  were 
  obtained 
  from 
  42. 
  In 
  34 
  of 
  the 
  villages 
  and 
  

   towns 
  larvae 
  of 
  S. 
  fasciata 
  were 
  found 
  (77 
  per 
  cent.), 
  in 
  35 
  larvae 
  of 
  Culex 
  duttoni 
  

   (79 
  per 
  cent.), 
  in 
  23 
  larvae 
  of 
  C. 
  decern 
  (52 
  per 
  cent.), 
  in 
  21 
  larvae 
  of 
  C. 
  tigripes 
  

   (47 
  per 
  cent.), 
  in 
  21 
  larvae 
  of 
  Culiciomyia 
  nebulosa 
  (47 
  per 
  cent.), 
  in 
  20 
  larvae 
  of 
  

   S. 
  vittata 
  (45 
  per 
  cent.), 
  in 
  4 
  larvae 
  of 
  Anopheles 
  costalis 
  (9 
  per 
  cent.) 
  and 
  in 
  3 
  larvae 
  

   of 
  C. 
  invidiosus 
  (6*8 
  per 
  cent.). 
  It 
  may 
  be 
  of 
  interest 
  to 
  compare 
  these 
  figures 
  with 
  

   the 
  records 
  of 
  domestic 
  breeding 
  larvae 
  obtained 
  at 
  Accra 
  during 
  the 
  past 
  two 
  

   years. 
  Of 
  1,121 
  samples 
  of 
  larvae 
  collected 
  by 
  the 
  sanitary 
  inspectors 
  and 
  forwarded 
  

   to 
  the 
  Laboratory 
  for 
  examination, 
  S. 
  fasciata 
  occurred 
  in 
  876 
  (78 
  per 
  cent.), 
  Culex 
  

   fatigams 
  in 
  221 
  (197 
  per 
  cent.), 
  A. 
  costalis 
  in 
  43 
  (3 
  per 
  cent.), 
  C. 
  decern 
  in 
  20 
  (1*7 
  

  

  