﻿414 
  

  

  W. 
  F. 
  FISKE. 
  

  

  especial 
  care 
  was 
  taken 
  to 
  make 
  the 
  count 
  and 
  test 
  a 
  fair 
  one, 
  in 
  connection 
  with 
  

   the 
  unusual 
  conditions 
  prevailing 
  on 
  the 
  island 
  in 
  January. 
  It 
  was 
  believed 
  at 
  

   that 
  time 
  that 
  on 
  account 
  of 
  shortage 
  of 
  food 
  the 
  insects 
  were 
  unable 
  to 
  breed 
  at 
  

   all 
  freely, 
  and 
  that 
  a 
  high 
  proportion 
  of 
  late 
  stages 
  of 
  pupae 
  would 
  confirm 
  this 
  

   fact. 
  Surely 
  enough, 
  the 
  proportion 
  of 
  late 
  stages 
  was 
  abnormally 
  high 
  — 
  and 
  

   surely 
  enough, 
  it 
  was 
  abnormally 
  low 
  in 
  March 
  when 
  food 
  had 
  become 
  more 
  plentiful 
  ; 
  

   but 
  whether 
  the 
  data 
  sustain 
  the 
  hypothesis 
  is 
  somewhat 
  doubtful. 
  A 
  more 
  complete 
  

   account 
  of 
  the 
  experiment 
  is 
  given 
  on 
  page 
  451. 
  

  

  The 
  proportion 
  of 
  living 
  puparia 
  to 
  empty 
  shells 
  varies 
  extremely, 
  and 
  variations 
  

   may 
  be 
  due 
  to 
  many 
  causes. 
  The 
  normal 
  proportions 
  would 
  appear 
  to 
  be 
  about 
  

   1 
  to 
  5 
  (if 
  there 
  is 
  a 
  " 
  normal 
  "), 
  but 
  there 
  are 
  so 
  many 
  things 
  which 
  might 
  explain 
  

   variations 
  from 
  it 
  that 
  data 
  are 
  of 
  slight 
  value, 
  except 
  perhaps 
  in 
  special 
  cases. 
  

   The 
  first 
  citation 
  in 
  the 
  accompanying 
  table 
  is 
  such 
  a 
  special 
  case. 
  The 
  find 
  was 
  made 
  

   at 
  a 
  spot 
  where 
  Varanus 
  had 
  habitually 
  basked, 
  but 
  there 
  were 
  no 
  recent 
  signs 
  

   of 
  the 
  presence 
  of 
  the 
  animal, 
  and, 
  with 
  its 
  abandonment 
  of 
  its 
  favourite 
  basking 
  

   spot, 
  the 
  flies 
  ceased 
  to 
  find 
  the 
  spot 
  attractive 
  breeding 
  ground. 
  

  

  Of 
  somewhat 
  greater 
  interest 
  is 
  the 
  percentage 
  of 
  empty 
  shells 
  which 
  have 
  been 
  

   eaten 
  or 
  destroyed 
  by 
  some 
  predatory 
  creature 
  — 
  ants, 
  or 
  beetle 
  larvae 
  — 
  which 
  extract 
  

   the 
  contents 
  without 
  completely 
  destroying 
  the 
  shell. 
  The 
  small 
  percentage 
  of 
  eaten 
  

   shells 
  and 
  the 
  large 
  percentage 
  from 
  which 
  the 
  flies 
  had 
  issued, 
  shown 
  in 
  Table 
  XXIX, 
  

   is 
  a 
  clear 
  indication 
  of 
  the 
  remarkable 
  degree 
  of 
  protection 
  afforded 
  by 
  good 
  breeding 
  

   places 
  to 
  the 
  pupae 
  of 
  Glossina. 
  The 
  subject 
  is 
  discussed 
  somewhat 
  more 
  fully 
  

   elsewhere 
  (p. 
  435). 
  

  

  Table 
  XXVIII. 
  

  

  Showing 
  Proportion 
  of 
  Living 
  Puparia 
  of 
  Glossina 
  palpalis 
  to 
  Empty 
  Shells 
  

  

  found 
  on 
  Islands 
  in 
  Victoria 
  Nyanza. 
  

  

  

  

  Date. 
  

  

  Finds 
  of 
  puparia 
  and 
  empty 
  shells. 
  

  

  Island. 
  

  

  

  

  

  

  

  

  Puparia. 
  

  

  Empty 
  

   shells. 
  

  

  Total. 
  

  

  Per 
  cent, 
  of 
  

   puparia. 
  

  

  Limnaiba 
  

  

  . 
  September 
  1914 
  

  

  3 
  

  

  283 
  

  

  286 
  

  

  1"1 
  % 
  

  

  Kiuwa 
  . 
  . 
  

  

  

  February 
  ,, 
  

  

  6 
  

  

  456 
  

  

  462 
  

  

  1*3 
  % 
  

  

  Kimmi, 
  Pt. 
  1* 
  

  

  

  }> 
  JJ 
  • 
  • 
  

  

  17 
  

  

  1077 
  

  

  1094 
  

  

  1-6 
  % 
  

  

  Damba, 
  Pt. 
  1 
  . 
  

  

  

  »» 
  >» 
  

  

  39 
  

  

  1163 
  

  

  1202 
  

  

  3-2 
  % 
  

  

  Kimmi, 
  Pt. 
  2* 
  

  

  

  }> 
  J5 
  

  

  59 
  

  

  1412 
  

  

  1471 
  

  

  4-0 
  % 
  

  

  Damba, 
  Pt. 
  2. 
  . 
  

  

  

  >» 
  », 
  

  

  797 
  

  

  4493 
  

  

  5290 
  

  

  11-1 
  % 
  

  

  Nsadzi 
  . 
  . 
  

  

  

  »» 
  >» 
  

  

  133 
  

  

  979 
  

  

  1112 
  

  

  H-9 
  % 
  

  

  Mugogoya 
  

  

  

  September 
  ,, 
  

  

  17 
  

  

  85 
  

  

  102 
  

  

  16-7 
  % 
  

  

  Zinga 
  . 
  . 
  

  

  

  »» 
  »> 
  

  

  144 
  

  

  478 
  

  

  622 
  

  

  23-1 
  % 
  

  

  Karambide 
  

  

  

  >5 
  JJ 
  

  

  31 
  

  

  79 
  

  

  110 
  

  

  28-2 
  % 
  

  

  Tavu 
  . 
  . 
  

  

  

  1915 
  

  

  207 
  

  

  344 
  

  

  601 
  

  

  34-4 
  % 
  

  

  Wema 
  . 
  . 
  

  

  

  February 
  1914 
  

  

  1755 
  

  

  3044 
  

  

  4799 
  

  

  36*6 
  % 
  

  

  Toti 
  

  

  il 
  and 
  . 
  

  

  Average 
  

  

  3208 
  

  

  13943 
  

  

  17151 
  

  

  18-7 
  % 
  

  

  * 
  Point 
  1 
  on 
  Kimmi 
  Island 
  was 
  in 
  a 
  cave, 
  where 
  the 
  empty 
  shells 
  might 
  be 
  expected 
  

   to 
  persist 
  indefinitely. 
  Point 
  2 
  is 
  the 
  total 
  for 
  several 
  finds 
  elsewhere 
  on 
  the 
  island. 
  

  

  