﻿34 
  

  

  H. 
  S. 
  Pratt, 
  

  

  rim 
  of 
  the 
  ovary 
  they 
  form 
  a 
  clistinct 
  mernbrane 
  whicli 
  surrounds 
  

   that 
  organ 
  and 
  binds 
  the 
  ovarioles 
  into 
  a 
  compact 
  mass. 
  In 
  Tipula 
  

   similar 
  conditions 
  prevail, 
  but 
  in 
  acldition 
  to 
  tbe 
  connective-tissue 
  

   fibres, 
  muscles-fibres 
  are 
  also 
  present. 
  In 
  both 
  cases 
  the 
  peritoneal 
  

   mernbrane 
  is 
  continuous 
  with 
  the 
  outer 
  covering 
  of 
  the 
  oviduct 
  and 
  

   also 
  of 
  the 
  terminal 
  thread. 
  Very 
  commonly, 
  however, 
  the 
  peritoneal 
  

   fibres, 
  instead 
  of 
  merely 
  being 
  spun 
  among 
  the 
  ovarioles 
  or 
  forming 
  

   a 
  mernbrane 
  about 
  all, 
  are 
  woven 
  into 
  a 
  distinct 
  mernbrane 
  about 
  

   each 
  one, 
  and 
  in 
  this 
  case 
  the 
  mernbrane 
  about 
  the 
  entire 
  ovary 
  is 
  

   usually 
  not 
  present. 
  Thus 
  in 
  Rhizotrogus, 
  Notonecta, 
  and 
  Carabus, 
  

   according 
  to 
  Leydig 
  (11, 
  p. 
  602), 
  each 
  ovariole 
  is 
  covered 
  with 
  a 
  

   thick 
  peritoneal 
  covering, 
  and 
  the 
  membranes 
  of 
  all 
  the 
  different 
  

   ovarioles 
  meet 
  at 
  the 
  distal 
  end 
  of 
  the 
  terminal 
  thread 
  in 
  a 
  common 
  

   mernbrane 
  which 
  connects 
  with 
  the 
  outer 
  covering 
  of 
  the 
  heart. 
  In 
  

   Musca, 
  a 
  very 
  near 
  relative 
  of 
  Melophagus 
  and 
  the 
  pupipars, 
  the 
  

   conditions 
  are 
  similar. 
  The 
  peritoneal 
  mernbrane, 
  according 
  to 
  Leydig 
  

   (11, 
  p. 
  574), 
  covers 
  each 
  ovariole 
  rather 
  loosely. 
  The 
  different 
  follicles 
  

   of 
  an 
  ovariole 
  are 
  separated 
  from 
  each 
  other 
  by 
  a 
  very 
  narrow 
  neck, 
  

   and 
  here 
  the 
  peritoneal 
  covering 
  is 
  not 
  applied 
  closely 
  to 
  the 
  tunica 
  

   propria, 
  but 
  passes 
  directly 
  from 
  one 
  follicle 
  across 
  to 
  another. 
  At 
  

   the 
  distal 
  tips 
  of 
  the 
  ovarioles 
  their 
  peritoneal 
  membranes 
  fuse 
  and 
  

   in 
  this 
  common 
  mernbrane 
  are 
  branched 
  muscle-fibres. 
  There 
  is 
  no 
  

   connection 
  between 
  the 
  ovary 
  and 
  the 
  outer 
  covering 
  of 
  the 
  heart. 
  

  

  Brandt 
  (1. 
  c. 
  p. 
  7) 
  sums 
  up 
  his 
  chapter 
  on 
  the 
  peritoneal 
  mern- 
  

   brane 
  in 
  insects 
  as 
  follows. 
  It 
  is 
  usually 
  present, 
  and 
  consists 
  of 
  

   connective-tissue 
  in 
  which 
  may 
  be 
  muscle-fibres; 
  but 
  it 
  is 
  an 
  accessory 
  

   and 
  not 
  a 
  necessary 
  part 
  of 
  the 
  reproductive 
  tract. 
  Its 
  function 
  is 
  to 
  

   hold 
  together 
  the 
  ovarioles. 
  The 
  muscle-fibres, 
  when 
  they 
  are 
  present, 
  

   serve 
  two 
  purposes, 
  they 
  assist 
  in 
  binding 
  together 
  the 
  ovarioles 
  and 
  

   also 
  cause 
  the 
  peristaltic 
  motion 
  which 
  has 
  been 
  observed 
  in 
  the 
  

   ovaries 
  of 
  Pulex, 
  Pieris 
  and 
  other 
  insects. 
  

  

  Considering, 
  Melophagus, 
  now, 
  in 
  the 
  light 
  of 
  the 
  foregoing, 
  we 
  

   see 
  that 
  its 
  peritoneal 
  mernbrane, 
  the 
  character 
  and 
  structure 
  of 
  which 
  

   at 
  first 
  sight 
  seem 
  so 
  aberrant, 
  is 
  really 
  peculiar 
  only 
  in 
  its 
  great 
  

   thickness 
  and 
  extent. 
  The 
  portion 
  which 
  forms 
  the 
  outer 
  sac 
  finds 
  

   its 
  counterpart 
  in 
  many 
  groups 
  of 
  insects 
  in 
  the 
  mernbrane 
  which 
  

   surrounds 
  and 
  holds 
  together 
  the 
  ovarioles, 
  but 
  in 
  no 
  other 
  insect, 
  

   so 
  far 
  as 
  I 
  know, 
  is 
  it 
  so 
  thick 
  and 
  composed 
  of 
  two 
  distinct 
  layers, 
  

   and 
  nowhere 
  do 
  the 
  muscles 
  play 
  so 
  important 
  a 
  role. 
  There 
  are 
  

   no 
  muscle-fibres 
  in 
  the 
  peritoneal 
  covering 
  of 
  the 
  ovarioles 
  in 
  Melo- 
  

  

  