﻿380 
  

  

  W. 
  F. 
  FISKE. 
  

  

  Catch 
  at 
  base 
  of 
  slope, 
  5 
  J 
  " 
  boy 
  hours/' 
  showed 
  density 
  

  

  (both 
  sexes) 
  of 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  15*50 
  

  

  Catch 
  haif-way 
  up 
  slope, 
  16 
  " 
  boy 
  hours," 
  showed 
  density 
  of 
  1*05 
  

  

  Catch 
  at 
  crest 
  of 
  slope, 
  28 
  " 
  boy 
  hours 
  " 
  showed 
  density 
  of 
  *26 
  

  

  (This 
  point 
  was 
  well 
  under 
  300 
  yards 
  from 
  the 
  water's 
  edge.) 
  

  

  Catch 
  in 
  old 
  plantations 
  beyond 
  the 
  crest 
  of 
  slope, 
  14 
  "boy 
  

  

  hours," 
  was 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  Nil. 
  

  

  This 
  is 
  probably 
  a 
  sharper 
  decline 
  in 
  density 
  than 
  usual, 
  but 
  not 
  excessively 
  so„ 
  

  

  V 
  (6). 
  Effect 
  of 
  Stashes 
  and 
  RivuSets 
  on 
  Range 
  of 
  the 
  Fly. 
  

  

  The 
  effect 
  of 
  lakes 
  or 
  streams 
  on 
  the 
  range 
  of 
  Glossina 
  pa 
  pedis 
  is 
  so 
  conspicuous 
  

   that 
  whenever 
  any 
  unusual 
  extension 
  of 
  its 
  range 
  inland 
  from 
  lake 
  shore 
  or 
  bank 
  

   of 
  large 
  stream 
  has 
  been 
  observed 
  it 
  has 
  almost 
  always 
  been 
  accounted 
  for 
  as 
  being 
  

   due 
  to 
  presence 
  of 
  small 
  streams, 
  marshes 
  or 
  humid 
  conditions 
  of 
  life 
  generally. 
  

   Therefore 
  if 
  any 
  island 
  were 
  to 
  show 
  inland 
  range 
  of 
  fly 
  too 
  much 
  in 
  excess 
  of 
  that 
  

   noted 
  as 
  '' 
  normal 
  " 
  in 
  the 
  preceding 
  sub- 
  section, 
  the 
  question 
  of 
  interior 
  conditions 
  

   with 
  respect 
  to 
  water 
  and 
  elevation 
  (dryness) 
  is 
  the 
  first 
  to 
  be 
  considered. 
  

  

  A 
  survey 
  of 
  the 
  islands 
  was 
  begun 
  in 
  January 
  1914 
  to 
  ascertain 
  and 
  measure 
  

   variations 
  in 
  degree 
  of 
  local 
  infestations, 
  as 
  they 
  might 
  be 
  correlated 
  with 
  differ 
  ences 
  

   in 
  local 
  environment. 
  Mostly 
  small 
  islands, 
  of 
  less 
  than 
  1,000 
  yards 
  short 
  diameter, 
  

   were 
  visited 
  ; 
  but 
  by 
  the 
  1st 
  September 
  out 
  of 
  a 
  total 
  of 
  some 
  40, 
  8 
  of 
  larger 
  size 
  

   had 
  been 
  included 
  in 
  the 
  survey, 
  and 
  conditions 
  with 
  respect 
  to 
  infestation 
  by 
  fly, 
  

   humidity 
  and 
  topography 
  of 
  the 
  interior 
  of 
  each 
  of 
  these 
  islands 
  were 
  found 
  to 
  be 
  

   as 
  stated 
  in 
  the 
  accompanying 
  table 
  (XVII). 
  

  

  Table 
  XVII. 
  

  

  Fly 
  Survey 
  of 
  Islands 
  in 
  Victoria 
  Nyanza 
  showinq 
  Lack 
  of 
  Correlation 
  between 
  

   Humidity 
  of 
  Interior 
  and 
  Infestation 
  by 
  Glossina 
  palpalis. 
  

  

  

  Conditions 
  

  

  in 
  Interior 
  

  

  Infestation 
  

  

  by 
  Glossina. 
  

  

  Island. 
  

  

  

  

  

  

  

  Topography. 
  

  

  Humidity. 
  

  

  Shore 
  Line. 
  

  

  Interior. 
  

  

  Wema 
  

  

  Hilly 
  . 
  . 
  

  

  Dryt 
  . 
  . 
  

  

  Dense 
  

  

  None. 
  

  

  Damba 
  

  

  Flat 
  . 
  . 
  

  

  Streams 
  and 
  

   marshes 
  

  

  Dense 
  

  

  Medium. 
  

  

  Kome 
  

  

  Hilly 
  . 
  . 
  

  

  Streams 
  

  

  Light 
  . 
  . 
  

  

  None. 
  

  

  Kitobo 
  . 
  . 
  

  

  Plateau 
  . 
  . 
  

  

  Dry* 
  . 
  . 
  

  

  Medium. 
  . 
  

  

  None. 
  

  

  Bukassa 
  . 
  

  

  Hilly 
  . 
  . 
  

  

  Dry* 
  

  

  Light 
  

  

  Light. 
  

  

  Bugaba 
  . 
  . 
  

  

  HiUy 
  . 
  . 
  

  

  Streams. 
  . 
  

  

  Light 
  

  

  None. 
  

  

  Bubembe 
  

  

  Hillv 
  . 
  . 
  

  

  Dryf 
  . 
  . 
  . 
  . 
  

  

  Light 
  . 
  . 
  

  

  None. 
  

  

  Bugovu 
  . 
  

  

  Hilly 
  . 
  . 
  

  

  Dryf 
  . 
  . 
  

  

  Light 
  

  

  None. 
  

  

  

  

  

  

  

  * 
  Careful 
  survey 
  showed 
  no 
  streams 
  near 
  points 
  of 
  interior 
  infestation, 
  

   f 
  Streams 
  may 
  exist 
  on 
  parts 
  of 
  islands 
  that 
  were 
  not 
  explored. 
  

  

  