﻿ON 
  A 
  NEW 
  SPECTKS 
  OF 
  THE 
  GENUS 
  HAPLOTAXfS. 
  313 
  

  

  and 
  '^ 
  coelomo 
  ducts 
  " 
  involved 
  in 
  the 
  more 
  recent 
  theory' 
  

   has 
  been 
  summarised 
  and 
  reviewed 
  by 
  Goodrich 
  (11), 
  and 
  

   has 
  been 
  accepted, 
  and 
  the 
  ideas 
  of 
  terminology 
  in 
  con- 
  

   connection 
  with 
  this 
  view 
  have 
  been 
  extended, 
  by 
  Lankester 
  

   in 
  his 
  'Treatise 
  on 
  Zoology 
  ' 
  (part 
  ii, 
  p. 
  32). 
  

  

  According 
  to 
  this 
  modern 
  view, 
  a 
  sharp 
  distinction, 
  

   founded 
  on 
  the 
  different 
  modes 
  of 
  origin, 
  is 
  drawn 
  betAveen 
  

   the 
  excretory 
  organs 
  and 
  the 
  genital 
  ducts 
  of 
  the 
  Oligo- 
  

   chaeta. 
  Tlie 
  former 
  being, 
  according 
  to 
  the 
  observations 
  of 
  

   Vejdovsky 
  (16) 
  and 
  of 
  Wilson 
  (17), 
  derived 
  from 
  epiblastic 
  

   ingrowths, 
  the 
  latter 
  from 
  mesoblastic 
  outgrowths 
  from 
  the 
  

   wall 
  of 
  the 
  ccelom. 
  There 
  is 
  still 
  some 
  doubt, 
  however, 
  as 
  

   to 
  whether 
  the 
  whole 
  nephridium 
  is 
  epiblastic, 
  for 
  whereas 
  

   Vejdovsky 
  and 
  Wilson 
  derive 
  it 
  from 
  a 
  '^nephric 
  cord" 
  of 
  

   cells 
  which 
  originate 
  from 
  a 
  superficial 
  teloblast, 
  Bergh 
  (9) 
  

   insists 
  that 
  the 
  whole 
  organ 
  is 
  developed 
  f 
  i-om 
  the 
  f 
  iinnel-cell, 
  

   which 
  he 
  regards 
  as 
  mesoblastic 
  in 
  origin, 
  and 
  not 
  as 
  having 
  

   pushed 
  its 
  way 
  from 
  tlie 
  surface 
  into 
  the 
  mesoblast. 
  If 
  this 
  

   statement 
  of 
  Bergh's 
  should 
  turn 
  out 
  to 
  be 
  true 
  — 
  and 
  it 
  is 
  a 
  

   case 
  of 
  one 
  good 
  observer 
  against 
  two 
  good 
  observers, 
  — 
  it 
  is 
  

   clear 
  that 
  a 
  modification 
  will 
  have 
  to 
  be 
  made 
  in 
  the 
  view 
  as 
  

   to 
  the 
  sharp 
  distinction 
  between 
  the 
  two 
  categories 
  of 
  organs. 
  

   However 
  this 
  may 
  be, 
  it 
  seems 
  clearly 
  and 
  satisfactorily 
  

   determined 
  that 
  the 
  genital 
  funnel 
  at 
  any 
  rate 
  is 
  formed 
  

   as 
  a 
  proliferation 
  of 
  the 
  coelomic 
  epithelium 
  covering 
  the 
  

   anterior 
  face 
  of 
  the 
  septum 
  to 
  which 
  the 
  nephi-idial 
  funnel 
  

   is 
  attached. 
  Now, 
  Goodrich 
  (12) 
  has 
  shown 
  in 
  a 
  series 
  of 
  

   valuable 
  memoirs 
  that 
  in 
  the 
  Polychasta 
  the 
  "coelomic 
  

   funnel 
  " 
  or 
  " 
  ccelomostome," 
  which 
  functions 
  as 
  a 
  genital 
  

   funnel, 
  may 
  become 
  grafted 
  on 
  to 
  a 
  nephi-idium, 
  with 
  or 
  

   without 
  the 
  loss 
  of 
  the 
  " 
  solenocy 
  tes 
  " 
  of 
  the 
  latter 
  organ. 
  

  

  It 
  appears 
  to 
  me 
  that 
  in 
  Haplotaxis 
  heterogyne 
  some- 
  

   thing 
  of 
  this 
  kind 
  has 
  occurred, 
  for 
  the 
  sperm-funnel 
  is 
  anato- 
  

   mically 
  quite 
  different 
  from 
  the 
  nephridial 
  funnel 
  of 
  the 
  neigh- 
  

   bouring 
  segments 
  ; 
  while 
  the 
  sperm-duct 
  is 
  pratically 
  in- 
  

   distinguishable 
  from 
  a 
  nephridial 
  tube, 
  and 
  it 
  originates 
  

   from 
  the 
  funnel 
  at 
  the 
  extreme 
  ventral 
  margin, 
  in 
  the 
  posi- 
  

  

  