﻿320 
  W. 
  BLAXLAND 
  BENHAM. 
  

  

  PLATE 
  17. 
  

   Figs. 
  16 
  — 
  24 
  represent 
  a 
  series 
  of 
  nearly 
  consecutive 
  transverse 
  sections 
  of 
  

   tlie 
  mature 
  specimen 
  through 
  the 
  first 
  pair 
  of 
  sperm-funnels 
  and 
  the 
  second 
  

   pair 
  of 
  testes. 
  (Camera, 
  x 
  120.) 
  

  

  In 
  fig. 
  16 
  the 
  entire 
  section, 
  with 
  all 
  the 
  organs 
  involved, 
  is 
  drawn 
  ; 
  in 
  the 
  

   rest 
  only 
  the 
  ventral 
  half 
  or 
  less 
  is 
  drawn. 
  In 
  fig. 
  16 
  the 
  spermatozoa 
  

   filling 
  the 
  first 
  sperm-sac 
  and 
  surrounding 
  the 
  gut 
  are 
  shown, 
  but 
  

   they 
  are 
  omitted 
  in 
  subsequent 
  figures. 
  The 
  worm 
  having 
  been 
  first 
  

   mounted 
  entire 
  and 
  somewhat 
  compressed, 
  the 
  organs 
  have 
  been 
  

   slightly 
  displaced, 
  so 
  that 
  the 
  right 
  and 
  left 
  organs 
  are 
  cut 
  through 
  at 
  

   different 
  planes 
  in 
  a 
  section. 
  On 
  the 
  right 
  side 
  the 
  course 
  of 
  the 
  

   sperm-duct 
  can 
  be 
  followed 
  easily 
  up 
  to 
  fig. 
  20, 
  where 
  it 
  has 
  reached 
  

   its 
  greatest 
  height 
  in 
  the 
  body 
  ; 
  it 
  then 
  descends, 
  and 
  the 
  last 
  trace 
  

   that 
  I 
  was 
  able 
  to 
  detect 
  (fig. 
  22) 
  was 
  close 
  to 
  the 
  chaetal 
  muscles; 
  

   the 
  base 
  of 
  the 
  chseta 
  is 
  cut 
  through 
  here, 
  but 
  the 
  shaft 
  comes 
  into 
  

   view 
  and 
  perforates 
  the 
  body-wall 
  nine 
  sections 
  further 
  along. 
  The 
  

   body-cavity 
  was 
  here 
  filled 
  with 
  a 
  coagulum, 
  which, 
  being 
  stained 
  in 
  

   hjemalum, 
  rendered 
  it 
  impossible 
  to 
  trace 
  the 
  sperm-duct 
  further 
  ; 
  

   but 
  on 
  the 
  left 
  side 
  the 
  duct 
  was 
  traced 
  right 
  up 
  to 
  the 
  epidermis 
  

   (fig. 
  24) 
  (see 
  also 
  fig. 
  29). 
  

  

  Figs. 
  25 
  — 
  27. 
  — 
  Three 
  consecutive 
  sections 
  through 
  part 
  of 
  the 
  left 
  sperm- 
  

   duct 
  in 
  the 
  region 
  shown 
  in 
  figs. 
  20, 
  21, 
  in 
  order 
  to 
  show 
  the 
  structure 
  of 
  the 
  

   duct 
  and 
  the 
  presence 
  of 
  spermatozoa 
  therein. 
  The 
  sperms 
  {sp.) 
  can 
  be 
  traced 
  in 
  

   several 
  other 
  sections, 
  even 
  when 
  the 
  duct 
  is 
  close 
  to 
  the 
  body-wall 
  (cf. 
  fig. 
  29). 
  

   (Camera, 
  ^V 
  liom. 
  imm., 
  Leitz; 
  X 
  oc. 
  3, 
  Leitz.) 
  

  

  Fig. 
  28. 
  — 
  A 
  section 
  cutting 
  the 
  sperm-duct 
  (of 
  Segment 
  XII) 
  longitudinally 
  

   near 
  the 
  upper 
  end 
  of 
  its 
  course, 
  showing 
  the 
  upward 
  and 
  downward 
  limbs 
  of 
  

   the 
  duct. 
  (Camera, 
  x 
  700.) 
  

  

  Fig. 
  29. 
  — 
  From 
  a 
  transverse 
  section 
  (fig. 
  24), 
  showing 
  the 
  sperm-duct 
  passing 
  

   through 
  the 
  muscles 
  of 
  the 
  body-wall 
  towards 
  the 
  epidermis, 
  which 
  is 
  reached 
  

   in 
  the 
  next 
  section 
  (not 
  figured). 
  Spermatozoa 
  are 
  seen 
  in 
  one 
  of 
  the 
  sections 
  

   across 
  the 
  duct. 
  (Camera, 
  X 
  700.) 
  

  

  Fig. 
  30. 
  — 
  The 
  copulatory 
  gland 
  from 
  Segment 
  XIII, 
  as 
  seen 
  in 
  a 
  transverse 
  

   section 
  of 
  the 
  mature 
  worm. 
  (Camera, 
  X 
  700; 
  details 
  under 
  ya- 
  hom. 
  imm.) 
  

  

  PLATE 
  18. 
  

   Figs. 
  31—36 
  show 
  the 
  sperm-funnel 
  and 
  the 
  commencement 
  of 
  its 
  duct- 
  

   Camera, 
  X 
  700; 
  details 
  under 
  J^ 
  hom. 
  imm.) 
  

  

  Figs. 
  31 
  — 
  34 
  are 
  four 
  consecutive 
  sections 
  through 
  the 
  first 
  sperm-funnel 
  

   on 
  the 
  right 
  side. 
  

  

  