﻿368 
  

  

  W. 
  F. 
  FISKE. 
  

  

  points 
  where 
  they 
  are 
  passing. 
  Under 
  such 
  conditions 
  nearly 
  all 
  flies 
  are 
  seeking 
  

   food, 
  and 
  all 
  are 
  equally 
  active, 
  as 
  clearly 
  shown 
  by 
  a 
  comparison 
  between 
  the 
  figures 
  

   presented 
  in 
  Table 
  XIV 
  and 
  those 
  presented 
  in 
  Table 
  XIII. 
  

  

  Table 
  XIV. 
  

  

  Catch 
  of 
  Fly 
  at 
  a 
  point 
  on 
  Shore 
  of 
  an 
  Island 
  where 
  Food 
  was 
  deficient, 
  and 
  

   where 
  nearly 
  all 
  Flies 
  were 
  seeking 
  it, 
  showing 
  equal 
  degree 
  of 
  Activity 
  on 
  the 
  

  

  part 
  of 
  both 
  Sexes. 
  

  

  Locality. 
  

  

  Date. 
  

  

  Hour. 
  

  

  Catch 
  of 
  Fly. 
  

  

  Density 
  of 
  Fly. 
  

  

  Total. 
  

  

  Females. 
  

  

  Males. 
  

  

  Females. 
  

  

  Total. 
  

  

  Landing 
  Place, 
  

   Kimmi 
  Island 
  

  

  (26th 
  Jan. 
  

   \ 
  1914 
  . 
  . 
  1 
  

  

  \ 
  

  

  1st 
  

  

  2nd 
  

  

  3rd 
  

  

  4th 
  

  

  5th 
  

  

  205 
  

   249 
  

   451 
  

   463 
  

  

  289 
  

  

  66-3 
  % 
  

   66-3 
  % 
  

   652 
  % 
  

   69-9 
  % 
  

   64-0 
  % 
  

  

  23 
  : 
  

   28 
  

   26 
  1 
  

   27-0 
  

   17-3 
  

  

  45 
  2 
  

   550 
  

   49-0 
  

   50 
  

   30-8 
  

  

  68-2 
  

   83-0 
  

   75- 
  1 
  

  

  77'0 
  

   48-1* 
  

  

  * 
  Falling 
  off 
  in 
  density 
  during 
  the 
  5th 
  hour 
  was 
  due 
  to 
  approach 
  of 
  evening. 
  The 
  sexes 
  

   remained 
  proportionately 
  as 
  active 
  as 
  before, 
  as 
  shown 
  by 
  the 
  female 
  percentage 
  for 
  this 
  

   period. 
  

  

  Ill 
  (c). 
  Effect 
  of 
  Shelter, 
  or 
  of 
  Type 
  of 
  Vegetation, 
  upon 
  Long-shore 
  Move- 
  

   ments 
  of 
  Fly 
  and 
  upon 
  Percentage 
  of 
  Females 
  in 
  the 
  Catch. 
  

  

  On 
  4th 
  September 
  1914, 
  a 
  catch 
  of 
  fly 
  was 
  made 
  under 
  unusual 
  circumstances 
  

   on 
  the 
  island 
  of 
  Bukassa. 
  The 
  shore 
  at 
  this 
  point 
  was 
  lined 
  with 
  a 
  very 
  dense 
  

   fringe 
  of 
  reeds 
  only 
  two 
  or 
  three 
  yards 
  in 
  width. 
  Inside 
  the 
  fringe 
  was 
  open 
  grass 
  

   land, 
  cropped 
  very 
  short 
  by 
  hippo, 
  with 
  scattered 
  clumps 
  of 
  thick 
  bush 
  and 
  trees 
  

   o 
  r 
  a 
  tort 
  affording 
  attractive 
  shelter 
  to 
  fly. 
  At 
  the 
  observation 
  point 
  itself 
  was 
  

   a 
  landing 
  place 
  of 
  hippo 
  with 
  a 
  trail 
  forming 
  a 
  tunnel 
  through 
  the 
  reeds. 
  The 
  

   prow 
  of 
  the 
  canoe 
  was 
  thrust 
  into 
  this 
  tunnel, 
  with 
  the 
  stern 
  projecting 
  beyond 
  

   the 
  reeds 
  into 
  the 
  open 
  lake, 
  and 
  collections 
  were 
  made 
  simultaneously 
  by 
  one 
  

   boy 
  stationed 
  in 
  the 
  stern 
  of 
  the 
  canoe, 
  outside 
  the 
  thick 
  fringe 
  of 
  reeds, 
  and 
  by 
  

   two 
  boys 
  at 
  and 
  near 
  the 
  point 
  where 
  the 
  hippo 
  trail 
  entered 
  the 
  opening, 
  inside 
  

   the 
  fringe 
  of 
  reeds. 
  These 
  reeds, 
  it 
  should 
  be 
  noted, 
  were 
  at 
  least 
  10 
  feet 
  in 
  height, 
  

   or 
  higher 
  than 
  tsetse 
  is 
  at 
  all 
  likely 
  to 
  rise 
  from 
  the 
  ground. 
  

  

  The 
  three 
  boys 
  worked 
  for 
  two 
  hours 
  with 
  the 
  following 
  results 
  : 
  

  

  Inside 
  Reeds. 
  Outside 
  Reeds. 
  

   Catch 
  per 
  boy 
  hour 
  — 
  - 
  

  

  Males 
  3-0 
  35 
  

  

  Females 
  . 
  . 
  .. 
  .. 
  .. 
  *5 
  7 
  "5 
  

  

  Female 
  Percentage 
  14 
  '3% 
  68 
  -2% 
  

  

  The 
  extraordinary 
  feature 
  of 
  this 
  catch 
  was 
  the 
  low 
  percentage 
  of 
  females 
  (14'3) 
  

   inside 
  and 
  the 
  high 
  percentage 
  (68*2) 
  outside 
  the 
  barrier 
  formed 
  by 
  the 
  reeds 
  ; 
  the 
  

   two 
  points 
  being 
  separated 
  by 
  not 
  more 
  than 
  10 
  yards. 
  

  

  