OF  THE  EEPEODUCTIVE  OEGANS  OF  THE  AJOTLIDS. 
141 
Fig.  2.  A view  of  two  generative  (a  and  a^)  and  three  pairs  (/I  g,  h)  of  non-generative 
or  ordinary  segmental  organs  from  JVais  filiformis ; a ^ is  the  male  organ ; 
(j?  b is  the  female.  The  masses  j are  testes ; b,  c are  the  ovaria ; e 
denote  the  umbrella-shaped  internal  extremities  of  the  generative  ciliated 
tubes,  a Jc  and  b.  The  dilated  portions,  a I,  c,  act  as  organs  of  expul- 
sion to  the  generative  products.  On  comparison  it  will  be  at  once  seen  that 
every  part  of  the  generative  segmental  organ  has  an  exact  counterpart  in  the 
ordinary  or  non-generative  organs,  g,  g h.  The  one  therefore  is  only  a 
modification  of  the  other. 
Fig.  3.  A view  of  the  generative  and  non-generative  segmental  organs  of  Lumbricus 
Jordanii  (mihi);  «,  attached  ends;  g,  c,  dilated  portion;  f,  testes; 
b,  b,  ovaria ; d,  coiled  highly  cihated  tube  terminating  in  a pyriform  open 
extremity,  e and  ^ ; Jc,  bridle. 
j m,  j m,  a pair  of  ordinary  segmental  organs ; B,  one  of  the  generative 
tubes  from  a young  worm. 
Fig.  4.  The  segmental  organs  of  another  species  of  Lumbricus  in  a very  young  state, 
Lumbricus  Kauii,  mihi;  a,  a,  a,  ordinary  organ;  B,  enlarged  view  of  the 
same ; C,  a generative  segmental  organ  having  attached  to  one  side  the  repro- 
ductive masses  c ; a,  mouth ; b,  outlet. 
Fig.  5.  One  of  the  ordinary  or  non-generative  segmental  organs  of  the  common  Earth- 
worm, Lumbricus  terrestris ; a^,  outlet ; b,  enlarged  portion  filled  with  minute 
entozoa,  at/  the  enlarged non-ciliated  portion  ends,  and  the  smooth-walled 
ciliated  portion,  j i,  begins ; from  i to  d extends  a curiously  camerated  and 
highly  vascular  division  of  the  tube,  lined  with  slowly  acting  minute  cilia. 
From  d to  e,  the  tube  is  again  smooth-walled,  dotted  with  the  nuclei  of  cells 
along  its  walls ; f,  the  ciliated  fan-shaped  termination  suspended  in  the  general 
cavity,  having  a very  wide  opening,  as  indicated  by  the  arrows ; n,  g,  g,  main 
vascular  trunk  of  the  organ ; h,  h,  botryoidal  appendages. 
Fig.  6.  An  outline  view  of  the  reproductive  masses  and  ciliated  tubes  of  fhe  common 
Earth-worm  in  situ : — ^,  i,  posterior  testicular  masses ; h,  its  corresponding  seg- 
mental organ ; f,  ovarian ; its  own  segmental  organ ; I,  calciferous  glands ; 
e,  second  ovarian  mass  with  its  own  segmental  organ ; d,  the  third  ovarian  mass 
and  organ;  c,j,  anterior  testicular  masses  with  their  own  segmental  organs, 
b,b\  a,  a,  ordinary  segmental  organs ; Jc,  median  structure. 
Fig.  7.  Diagram  showing  the  mode  in  which  the  duct  of  the  testes  (a)  opens  into  the 
ciliated  tube  (b)  to  form  a common  duct  (c)  opening  outwards  at  d. 
Fig.  8.  Shows  the  mode  in  which  the  ovarian  masses  (a)  surround  the  cihated  tube,  c b. 
Plate  VII. 
Fig.  9.  A full  and  complete  representation,  in  the  mature  condition,  of  the  ovarian  seg- 
mental organ  of  the  common  Leech  {Hirudo  officinalis) ; a,  a®,  the  ends  of  the 
MDCCCLVIII.  u 
