﻿452 
  

  

  W. 
  F. 
  FLSKE. 
  

  

  16*1 
  per 
  cent, 
  of 
  late 
  stages. 
  There 
  should 
  have 
  been 
  16 
  early 
  to 
  6 
  late 
  stages, 
  

   whereas 
  there 
  were 
  found 
  approximately 
  32 
  early 
  to 
  6 
  late, 
  or 
  almost 
  exactly 
  

   twice 
  more 
  than 
  normal, 
  indicating 
  that 
  the 
  flies 
  were 
  depositing 
  twice 
  as 
  many 
  

   young 
  as 
  were 
  being 
  deposited 
  two 
  or 
  three 
  weeks 
  before. 
  

  

  The 
  experiments 
  were 
  conducted 
  with 
  sufficient 
  care 
  to 
  eliminate 
  most 
  chances 
  

   of 
  error, 
  and 
  little 
  doubt 
  is 
  felt 
  that 
  there 
  was 
  actually 
  a 
  falling 
  off 
  in 
  the 
  number 
  

   of 
  young 
  produced 
  followed 
  by 
  a 
  proportionately 
  heavy 
  increase 
  in 
  numbers. 
  The 
  

   only 
  question 
  is 
  whether 
  this 
  falling 
  off 
  was 
  due, 
  as 
  assumed, 
  to 
  the 
  temporary 
  

   abandonment 
  of 
  the 
  island 
  by 
  host 
  animals, 
  and 
  whether 
  this 
  in 
  its 
  turn 
  was 
  due, 
  

   as 
  assumed, 
  to 
  increase 
  in 
  density 
  of 
  fly. 
  The 
  experiment 
  turned 
  out 
  exactly 
  as 
  it 
  

   should, 
  in 
  accordance 
  with 
  the 
  working 
  hypothesis. 
  It 
  sustains 
  the 
  hypothesis, 
  

   though 
  it 
  does 
  not 
  prove 
  it. 
  The 
  point 
  in 
  question 
  is, 
  in 
  fact, 
  one 
  that 
  could 
  only 
  

   be 
  proved 
  by 
  investigations 
  conducted 
  over 
  a 
  considerable 
  period 
  on 
  an 
  island 
  

   like 
  Kimmi, 
  with 
  exact 
  observations 
  on 
  the 
  movements 
  of 
  host 
  animals 
  and 
  

   variations 
  in 
  degree 
  of 
  infestation. 
  

  

  Table 
  XXXIX. 
  

  

  Showing 
  Variation 
  in 
  Infestation 
  of 
  Kimmi 
  Island 
  between 
  January 
  and 
  March 
  

  

  1914. 
  

  

  

  Infestation 
  in 
  January. 
  

  

  Infestation 
  in 
  March. 
  

  

  Observation 
  point. 
  

  

  Catch. 
  

  

  Male 
  

  

  density. 
  

  

  Female 
  

   percentage. 
  

  

  Catch. 
  

  

  Male 
  

   density. 
  

  

  Female 
  

   percentage. 
  

  

  S.W. 
  Point 
  

   N.W. 
  Point 
  

   S.E. 
  Point 
  

   Southern 
  Shore 
  

  

  384 
  

  

  272 
  

   506 
  

   276 
  

  

  23-3 
  

   43-3 
  

  

  39-5 
  

  

  42-7 
  

  

  62-9 
  % 
  

   52-2 
  % 
  

   53-2 
  % 
  

   53-0 
  o 
  /o 
  

  

  208 
  

   502 
  

   351 
  

   292 
  

  

  19-1 
  

   45-6 
  

   31 
  7 
  

  

  31-5 
  

  

  26-8 
  % 
  

   27-3 
  % 
  

  

  27-4 
  o/ 
  o 
  

   13-7 
  % 
  

  

  Totals 
  and 
  Averages 
  . 
  . 
  

  

  1438 
  

  

  372 
  

  

  53-3 
  % 
  

  

  1353 
  

  

  32-0 
  

  

  23-7 
  % 
  

  

  The 
  only 
  other 
  localities 
  visited 
  in 
  the 
  course 
  of 
  these 
  investigations 
  in 
  which 
  the 
  

   female 
  percentage 
  was 
  in 
  excess 
  of 
  50 
  (for 
  the 
  entire 
  island 
  or 
  district) 
  are: 
  — 
  

  

  (1) 
  Bunyama 
  Island 
  (data 
  mislaid*) 
  

  

  (2) 
  Bale 
  Beach 
  and 
  Mujuzi 
  Creek 
  colony 
  . 
  . 
  . 
  . 
  64*6% 
  

  

  (3) 
  Bukakata 
  South 
  colony 
  .. 
  .. 
  .. 
  .. 
  51'0% 
  

  

  (4) 
  Kaziru 
  District 
  (Buddu) 
  50-6% 
  

  

  * 
  Since 
  recovered, 
  but 
  not 
  included 
  here. 
  

  

  In 
  none 
  of 
  these 
  localities 
  did 
  it 
  appear 
  that 
  scarcity 
  of 
  food 
  was 
  due 
  to 
  density 
  

   of 
  fly. 
  The 
  fly 
  was 
  suffering 
  from 
  want 
  of 
  food, 
  certainly, 
  but 
  merely 
  because 
  there 
  

   was 
  so 
  little 
  food 
  and 
  this 
  so 
  hard 
  to 
  find. 
  Conditions 
  were 
  as 
  they 
  would 
  become 
  

   on 
  Kimmi 
  if 
  the 
  host 
  animals 
  abandoned 
  the 
  island 
  permanently, 
  all 
  save 
  two 
  or 
  

   three 
  Varanus 
  or 
  a 
  single 
  crocodile. 
  The 
  point 
  where 
  food 
  chanced 
  to 
  be, 
  at 
  any 
  

   time, 
  would 
  then 
  be 
  a 
  " 
  colony 
  centre 
  " 
  — 
  exactly 
  like 
  the 
  colony 
  centres 
  in 
  the 
  

  

  