﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  423 
  

  

  A 
  certain 
  correlation 
  between 
  extent 
  or 
  character 
  of 
  breeding 
  grounds 
  and 
  degree 
  

   of 
  infestation 
  is 
  at 
  once 
  apparent, 
  but 
  the 
  lack 
  of 
  it 
  is 
  rattier 
  more 
  conspicuous 
  

   than 
  the 
  presence 
  of 
  it. 
  The 
  scarcity 
  of 
  fly 
  on 
  the 
  island 
  of 
  Lukalu 
  West 
  and 
  the 
  

   islet 
  south 
  of 
  Dziru, 
  and 
  its 
  complete 
  absence 
  on 
  the 
  very 
  small 
  islets 
  of 
  Lukalu 
  

   East 
  and 
  Kukassu, 
  notwithstanding 
  the 
  presence 
  of 
  good 
  and 
  extensive 
  breeding 
  

   places, 
  as 
  well 
  as 
  the 
  lightness 
  of 
  infestation 
  on 
  many 
  of 
  the 
  islets 
  falling 
  in 
  the 
  second 
  

   group 
  (Kizima, 
  Kirengi, 
  Ziro, 
  etc.), 
  is 
  proof 
  that 
  something 
  else 
  that 
  is 
  requisite 
  to 
  

   the 
  life 
  of 
  the 
  species 
  is 
  either 
  deficient 
  or 
  lacking 
  altogether. 
  

  

  Yet 
  more 
  significant 
  is 
  the 
  relatively 
  heavy 
  infestation 
  of 
  islands 
  like 
  Karambidi, 
  

   Mugogoya, 
  or 
  most 
  strikingly, 
  Lula, 
  on 
  which 
  breeding 
  grounds 
  of 
  the 
  sand 
  or 
  gravel 
  

   type 
  are 
  poor, 
  very 
  poor 
  or 
  lacking 
  altogether. 
  

  

  The 
  food 
  supply 
  was 
  adequate 
  or 
  much 
  more 
  than 
  adequate 
  on 
  virtually 
  all 
  these 
  

   islets, 
  with 
  the 
  single 
  exception 
  of 
  Kimmi. 
  Both 
  crocodile 
  and 
  Varanus 
  were 
  

   common 
  on 
  nearly 
  all 
  the 
  smallest 
  islets, 
  and 
  particularly 
  so 
  on 
  certain 
  of 
  them 
  

   that 
  were 
  least 
  densely 
  or 
  not 
  at 
  all 
  infested. 
  

  

  Many 
  other 
  factors 
  were 
  taken 
  into 
  account, 
  but 
  none 
  seemed 
  adequate 
  to 
  explain 
  

   the 
  facts, 
  and 
  in 
  August 
  1914 
  it 
  was 
  resolved 
  to 
  extend 
  the 
  fly 
  survey 
  to 
  include 
  

   long 
  reaches 
  of 
  shore 
  on 
  the 
  larger 
  islands 
  and 
  mainland 
  on 
  the 
  theory 
  that 
  mere 
  

   insularity 
  {i.e., 
  excessive 
  insularity 
  of 
  tiny 
  islets 
  of 
  only 
  a 
  few 
  acres 
  in 
  extent) 
  

   might 
  prove 
  the 
  principle 
  source 
  of 
  confusion. 
  A 
  fairly 
  solid 
  foundation 
  for 
  this 
  

   theory 
  was 
  subsequently 
  found. 
  

  

  The 
  first 
  extensive 
  reach 
  of 
  shore 
  systematically 
  surveyed 
  was 
  the 
  circumference 
  

   of 
  the 
  island 
  of 
  Bugaba 
  (fig. 
  7), 
  a 
  reach 
  of 
  some 
  16J 
  miles. 
  The 
  results 
  were 
  

   most 
  encouraging. 
  A 
  summary 
  follows. 
  

  

  The 
  characters 
  of 
  the 
  foreshore 
  of 
  the 
  lake, 
  and 
  of 
  the 
  soil 
  at 
  points 
  along 
  the 
  shore 
  

   is 
  indicated 
  in 
  the 
  chart 
  by 
  letters, 
  as 
  follows. 
  

  

  Soils 
  of 
  types 
  which 
  will 
  serve 
  as 
  breeding 
  grounds 
  : 
  — 
  

  

  A. 
  Brown 
  beach 
  gravel 
  and 
  sand. 
  

  

  B. 
  White 
  sand, 
  mixed 
  with 
  coarse 
  gravel 
  or 
  small 
  pebbles. 
  

  

  C. 
  Fine 
  sandy 
  soil, 
  or 
  loose 
  sandy 
  loam 
  a 
  little 
  back 
  from 
  the 
  beach 
  line. 
  

  

  D. 
  Pebbles 
  mixed 
  with 
  a 
  little 
  sand 
  and 
  gravel. 
  

  

  E. 
  Flat 
  rock, 
  with 
  sand 
  or 
  gravel 
  lodged 
  in 
  depressions. 
  

  

  F. 
  Wet 
  sandy 
  beaches, 
  overgrown 
  with 
  grass 
  to 
  water's 
  edge. 
  

   Soils 
  and 
  shores 
  of 
  types 
  which 
  do 
  not 
  serve 
  as 
  breeding 
  grounds 
  : 
  — 
  

  

  G-. 
  Bold 
  rocky 
  shore, 
  sometimes 
  precipitous. 
  

   H. 
  Rocky 
  shore, 
  neither 
  very 
  bold 
  nor 
  very 
  flat. 
  

   I. 
  Flat 
  rocky 
  shore 
  (without 
  sand 
  or 
  gravel). 
  

   J. 
  Rock 
  and 
  marsh 
  ; 
  or 
  marsh 
  with 
  rocks 
  protruding. 
  

   K. 
  Clay 
  banks, 
  with 
  or 
  without 
  marshy 
  foreshore. 
  

   L. 
  Marsh, 
  with 
  some 
  floating 
  vegetation 
  (sudd). 
  

   Shelter 
  immediately 
  back 
  from 
  the 
  fore-shore 
  : 
  — 
  

   M. 
  Forest, 
  or 
  very 
  thick 
  bush. 
  ^ 
  

  

  N. 
  Scattered 
  bush, 
  with 
  open 
  spaces. 
  ISufficient 
  shelter 
  for 
  fly. 
  

  

  0. 
  Thick 
  bush 
  fringe, 
  with 
  grass 
  land 
  behind. 
  J 
  

  

  P. 
  Thin 
  bush 
  fringe, 
  with 
  grass 
  land 
  behind. 
  JT 
  nsuffic 
  ient 
  shelter 
  for 
  fly. 
  

   Q. 
  Open 
  grass 
  land 
  to 
  water 
  s 
  edge. 
  J 
  J 
  

  

  It 
  is 
  to 
  be 
  noted 
  that 
  concentration 
  of 
  fly 
  is 
  apt 
  to 
  be 
  greatest 
  at 
  a 
  short 
  distance 
  

   from 
  the 
  breeding 
  ground. 
  

  

  At 
  point 
  43 
  shelter 
  at 
  the 
  breeding 
  ground 
  is 
  insufficient 
  and 
  there 
  is 
  a 
  double- 
  

   peaked 
  colony, 
  greatest 
  concentration 
  occurring 
  on 
  both 
  sides, 
  about 
  equally. 
  

  

  