﻿276 
  W. 
  HLAXr-ANI) 
  BBNHAM. 
  

  

  the 
  Segments 
  VII 
  to 
  XI 
  are 
  occupied 
  by 
  sperm-masses, 
  and 
  

   none 
  are 
  recorded 
  posteriorly; 
  Avliereas 
  in 
  the 
  South 
  American 
  

   species 
  Beddard 
  finds 
  the 
  "sperm-sacs" 
  extending 
  back- 
  

   wards 
  to 
  Segment 
  XX 
  in 
  P. 
  alb 
  us, 
  or 
  even 
  to 
  the 
  twenty- 
  

   sixth 
  segment 
  in 
  P. 
  niger, 
  and 
  makes 
  no 
  mention 
  of 
  pre- 
  

   clitellar 
  sacs; 
  but 
  in 
  P. 
  branch 
  iatus 
  he 
  states 
  that 
  no 
  

   special 
  sperm-sacs 
  exist, 
  but 
  Segments 
  VII 
  to 
  IX 
  are 
  filled 
  

   with 
  developing 
  sperms. 
  Thus 
  a 
  second 
  possible 
  generic 
  

   difference 
  is 
  seen 
  to 
  be 
  negatived. 
  

  

  The 
  efferent 
  apparatus 
  (fig. 
  5) 
  is 
  perhaps 
  the 
  most 
  interest- 
  

   ing 
  anatomical 
  feature 
  in 
  the 
  worm 
  of 
  this 
  genus, 
  as 
  Beddard 
  

   has 
  emphasised 
  in 
  his 
  memoir 
  (2). 
  The 
  funnel 
  of 
  the 
  sperm- 
  

   duct 
  is 
  a 
  circular, 
  flattened 
  disc, 
  carried 
  on 
  septum 
  Xl/XII, 
  

   but 
  not 
  projecting 
  freely 
  into 
  the 
  segment, 
  as 
  is 
  most 
  

   commonly 
  the 
  case, 
  for 
  its 
  margin 
  is 
  surrounded 
  by 
  a 
  circle 
  

   of 
  non-ciliated 
  cells 
  which 
  are 
  continuous 
  with 
  the 
  septum. 
  

   It 
  is 
  true 
  that 
  the 
  septum 
  here 
  bulges 
  forwards 
  (in 
  sections), 
  

   carrying 
  the 
  funnel 
  a 
  little 
  distance 
  into 
  the 
  cavity 
  of 
  the 
  

   segment, 
  but 
  the 
  funnel 
  itself 
  is 
  morphologically 
  flush 
  with 
  

   the 
  anterior 
  surface 
  of 
  the 
  septum. 
  The 
  cilia 
  covering 
  the 
  

   funnel 
  are 
  quite 
  short, 
  though 
  in 
  examining 
  the 
  entire 
  indi- 
  

   vidual 
  I 
  at 
  first 
  mistook 
  a 
  bunch 
  of 
  sperms 
  for 
  long 
  cilia, 
  

   and 
  in 
  sections 
  a 
  similar 
  mistake 
  may 
  readily 
  be 
  made. 
  The 
  

   sperm-duct 
  passes 
  away 
  from 
  the 
  centre 
  of 
  this 
  flat 
  funnel, 
  

   and 
  after 
  a 
  few 
  convolutions 
  in 
  a 
  dorso-ventral 
  direction 
  

   immediately 
  behind 
  the 
  septum, 
  passes 
  backwards 
  towards 
  

   the 
  hinder 
  wall 
  of 
  Segment 
  XII; 
  it 
  here 
  enters 
  a 
  conical 
  

   organ, 
  which 
  is 
  a 
  sac 
  i})-^.) 
  enclosing 
  a 
  protrusible 
  penis. 
  

   At 
  the 
  point 
  of 
  enti-y 
  the 
  sperm-duct 
  is 
  joined 
  by 
  a 
  great 
  

   spermiducal 
  gland 
  {gl.), 
  which 
  is 
  cylindrical 
  and 
  somewhat 
  

   coiled, 
  or 
  pei-haps 
  one 
  should 
  say 
  undulating. 
  The 
  spermiducal 
  

   gland 
  occupies 
  the 
  whole 
  of 
  Segment 
  XII, 
  and 
  even 
  pushes 
  

   backwards 
  the 
  posterior 
  septum 
  of 
  this 
  segment. 
  It 
  diminishes 
  

   in 
  diameter 
  before 
  its 
  junction 
  with 
  the 
  sperm-duct, 
  and 
  this 
  

   narrow 
  region 
  may 
  be 
  termed 
  the 
  neck 
  (n). 
  

  

  The 
  gland 
  has 
  a 
  structure 
  similar 
  to 
  that 
  described 
  by 
  

   Beddard 
  for 
  P. 
  albus, 
  and 
  to 
  the 
  " 
  appeudix 
  of 
  the 
  vas 
  

  

  