﻿GLOSSINA 
  MOESITANS 
  IN 
  NORTHERN 
  RHODESIA. 
  53 
  

  

  When 
  a 
  fly 
  containing 
  a 
  blood 
  clot 
  is 
  dissected, 
  the 
  distortion 
  of 
  the 
  contents 
  

   of 
  the 
  abdomen 
  is 
  found 
  to 
  be 
  considerable. 
  In 
  an 
  extreme 
  case 
  the 
  viscera 
  are 
  

   pressed 
  into 
  a 
  flat 
  mass 
  against 
  the 
  dorsal 
  body-wall 
  and 
  come 
  away 
  in 
  a 
  cake. 
  

   If 
  an 
  attempt 
  is 
  made 
  to 
  unravel 
  the 
  gut 
  it 
  is 
  found 
  to 
  be 
  much 
  flattened 
  and 
  

   breaks 
  repeatedly. 
  The 
  small 
  development 
  of 
  the 
  fat-body 
  is 
  evidence 
  of 
  

   malnutrition. 
  Thee 
  fleet 
  on 
  the 
  generative 
  organs 
  of 
  the 
  female 
  is 
  very 
  apparent. 
  

   The 
  ovaries 
  of 
  a 
  newly 
  emerged 
  fly 
  consist 
  of 
  a 
  couple 
  of 
  pear-shaped 
  bodies, 
  the 
  broad 
  

   ends 
  of 
  which 
  are 
  connected 
  with 
  the 
  short 
  thick 
  oviduct 
  which 
  enlarges 
  into 
  the 
  

   uterus. 
  The 
  spermathecae, 
  a 
  pair 
  of 
  chitinised 
  capsules, 
  are 
  connected 
  but 
  have 
  

   separate 
  short 
  ducts 
  which 
  open 
  close 
  together 
  into 
  the 
  anterior 
  end 
  of 
  the 
  uterus 
  

   on 
  the 
  ventral 
  surface. 
  The 
  branched 
  tubular 
  system 
  which 
  secretes 
  the 
  food 
  of 
  the 
  

   developing 
  larva 
  is 
  closely 
  attached 
  to 
  the 
  uterus 
  and 
  opens 
  into 
  it 
  on 
  a 
  papilla 
  just 
  

   posterior 
  to 
  the 
  opening 
  of 
  the 
  spermathecal 
  ducts. 
  The 
  system 
  and 
  the 
  development 
  

   of 
  the 
  eggs 
  and 
  larvae 
  have 
  been 
  very 
  fully 
  described 
  in 
  the 
  case 
  of 
  G. 
  palpalis* 
  As 
  

   the 
  generative 
  products 
  mature, 
  an 
  egg 
  in 
  each 
  ovary 
  grows 
  considerably 
  in 
  size, 
  

   one 
  being 
  usually 
  more 
  advanced 
  than 
  the 
  other. 
  The 
  mature 
  egg 
  is 
  of 
  the 
  typical 
  

   Muscid 
  form, 
  being 
  elongated 
  and 
  slightly 
  kidney-shaped. 
  In 
  the 
  case 
  of 
  a 
  female 
  

   fly 
  which 
  contains 
  a 
  large 
  clot, 
  the 
  ovaries 
  are 
  doubled 
  forward 
  over 
  the 
  uterus 
  in 
  

   such 
  a 
  way 
  that 
  the 
  mature 
  egg 
  is 
  unable 
  to 
  pass 
  down. 
  The 
  eggs 
  however 
  continue 
  

   to 
  develop 
  and 
  the 
  oldest 
  one 
  becomes 
  crushed 
  completely 
  out 
  of 
  shape 
  (fig. 
  1). 
  In 
  

  

  Fig. 
  1. 
  Showing 
  the 
  effect 
  on 
  the 
  developing 
  eggs 
  of 
  G. 
  morsitans 
  of 
  a 
  

  

  blood 
  clot 
  in 
  the 
  sucking 
  stomach 
  ; 
  ventral 
  view 
  : 
  — 
  a, 
  a, 
  fully 
  developed 
  

  

  healthy 
  eggs 
  ; 
  b, 
  oldest 
  egg 
  crushed 
  by 
  pressure 
  ; 
  c, 
  undeveloped 
  eggs 
  ; 
  

  

  d, 
  duct 
  of 
  feeding 
  tubes 
  ; 
  e, 
  spermathecae 
  ; 
  /, 
  uterus. 
  

  

  the 
  case 
  figured 
  the 
  first 
  egg 
  is 
  seen 
  to 
  have 
  been 
  partly 
  forced 
  into 
  the 
  oviduct, 
  com- 
  

   pletely 
  blocking 
  up 
  the 
  lumen. 
  In 
  two 
  instances 
  in 
  which 
  pupation 
  of 
  the 
  larvae 
  

   commenced 
  in 
  the 
  uterus 
  the 
  effect 
  of 
  the 
  pressure 
  was 
  well 
  marked. 
  Pupation 
  was 
  

   not 
  completed 
  in 
  either 
  case, 
  the 
  cuticle 
  of 
  the 
  larvae 
  becoming 
  dark, 
  but 
  remaining 
  of 
  

   a 
  leathery 
  texture. 
  In 
  one 
  of 
  these 
  the 
  pressure 
  of 
  the 
  ovaries 
  on 
  the 
  uterus 
  had 
  

   caused 
  a 
  deep 
  depression 
  in 
  the 
  larva 
  just 
  posterior 
  to 
  the 
  mouth. 
  In 
  the 
  other 
  case 
  

   the 
  posterior 
  cap 
  was 
  doubled 
  over 
  laterally 
  with 
  one 
  of 
  the 
  protuberances 
  pressing 
  

   against 
  the 
  body 
  of 
  the 
  larva. 
  Considering 
  the 
  frequency 
  with 
  which 
  the 
  clots 
  are 
  

   formed 
  it 
  is 
  remarkable 
  that 
  a 
  diet 
  of 
  avian 
  blood 
  compares 
  so 
  favourably 
  with 
  a 
  

   diet 
  of 
  mammalian 
  blood. 
  

  

  * 
  Minchin, 
  Proceedings 
  of 
  the 
  Koyal 
  Society, 
  Vol. 
  B76, 
  p. 
  543 
  ; 
  Roubaud, 
  La 
  Maladie 
  

   du 
  Sommeil, 
  1909, 
  pp. 
  427-452. 
  

  

  