﻿Reproductive 
  organs 
  of 
  Taenia 
  pisiformis. 
  367 
  

  

  part, 
  the 
  shell 
  gland 
  and 
  the 
  posterior 
  end 
  of 
  the 
  uterus 
  (Figs. 
  2 
  

   and 
  3). 
  This, 
  as 
  already 
  described, 
  is 
  an 
  enlargement 
  at 
  the 
  proximal 
  

   end 
  of 
  the 
  vagina 
  and 
  is 
  histologically 
  similar 
  to 
  the 
  anläge 
  of 
  the 
  

   latter 
  (Fig. 
  16). 
  In 
  this 
  mass 
  the 
  various 
  ducts 
  arise 
  by 
  a 
  grouping 
  

   of 
  certain 
  cells 
  about 
  a 
  central 
  point, 
  where 
  a 
  lumen 
  soon 
  appears 
  

   by 
  a 
  process 
  of 
  splitting 
  as 
  already 
  described 
  for 
  the 
  vagina. 
  About 
  

   this 
  central 
  lumen 
  two 
  layers 
  of 
  cells 
  arrange 
  themselves, 
  with 
  a 
  

   basement 
  membrane 
  separating 
  them, 
  which 
  arises 
  as 
  described 
  above 
  

   for 
  the 
  vagina 
  and 
  vas 
  deferens. 
  The 
  thickness 
  of 
  the 
  two 
  layers 
  

   varies 
  in 
  different 
  parts 
  of 
  the 
  oviduct. 
  The 
  cells 
  of 
  the 
  inner 
  

   layer 
  or 
  epithelium 
  are 
  in 
  general 
  low 
  columnar 
  or 
  cubical 
  in 
  form, 
  

   and 
  arranged 
  in 
  a 
  single 
  layer; 
  while 
  those 
  of 
  the 
  outer 
  layer 
  are 
  

   irregular 
  in 
  shape 
  and 
  may 
  be 
  arranged 
  in 
  more 
  than 
  one 
  layer 
  

   (Fig. 
  17). 
  The 
  latter 
  ultimately 
  becomes 
  thinned 
  out 
  and 
  forms 
  a 
  

   layer 
  of 
  irregular 
  cells 
  bounding 
  the 
  duct 
  (Fig. 
  18). 
  The 
  oviduct 
  

   retains 
  its 
  epithelium 
  in 
  its 
  original 
  form 
  until 
  its 
  function 
  has 
  been 
  

   performed. 
  Arising 
  as 
  it 
  does 
  from 
  an 
  anläge 
  common 
  to 
  itself, 
  the 
  

   shell 
  gland 
  and 
  the 
  posterior 
  end 
  of 
  the 
  uterus, 
  the 
  oviduct 
  is 
  con- 
  

   nected 
  with 
  the 
  latter 
  from 
  the 
  outset 
  and 
  the 
  lumina 
  of 
  the 
  two 
  

   communicate 
  with 
  each 
  other 
  at 
  an 
  early 
  stage. 
  

  

  Sommée 
  (1874) 
  in 
  Taenia 
  mediocanellata 
  and 
  solium^ 
  Roboz 
  (1882) 
  

   in 
  SolenopJiorus 
  megalocephaJus, 
  and 
  Balss 
  (1908) 
  in 
  Anoplocephala 
  

   magna 
  etc. 
  describe 
  the 
  oviduct 
  as 
  lined 
  by 
  cilia 
  ^), 
  which 
  are 
  directed 
  

   toward 
  the 
  seminal 
  receptacle 
  and 
  the 
  "Samenfäden 
  nur 
  bis 
  zur 
  

   Einmündungsstelle 
  des 
  Receptaculum 
  seminis 
  in 
  der 
  Keimleiter 
  vor- 
  

   dringen 
  lassen, 
  wo 
  sie 
  das 
  ihnen 
  durch 
  die 
  Ringmuskeln 
  entgegen- 
  

   geschobeue 
  Ei 
  befruchten" 
  Balss 
  (1. 
  c, 
  p. 
  282). 
  In 
  Taenia 
  pisiformis 
  

   these 
  cilia 
  are 
  absent 
  and 
  fertilization 
  apparently 
  occurs 
  in 
  the 
  

   uterus, 
  at 
  least 
  I 
  have 
  found 
  instances 
  of 
  uterine 
  eggs 
  containing 
  

   but 
  slightly 
  altered 
  spermatozoa. 
  The 
  main 
  branches 
  of 
  the 
  oviduct 
  

   develop 
  similarly 
  from 
  cords 
  of 
  parenchyma 
  cells. 
  They 
  remain 
  

   however 
  for 
  a 
  considerable 
  time 
  as 
  cords 
  of 
  cells 
  without 
  distinct 
  

   lumina 
  (Fig. 
  27). 
  The 
  basement 
  membrane 
  develops 
  either 
  in 
  the 
  

   syncitial 
  cord 
  or 
  between 
  it 
  and 
  the 
  parenchyma 
  by 
  a 
  condensation 
  

   of 
  fibrillae, 
  while 
  the 
  contained 
  cells 
  gradually 
  degenerate, 
  only 
  a 
  

   few 
  persisting 
  as 
  flattened 
  and 
  widely 
  separated 
  elements 
  lying 
  on 
  

  

  terminology 
  and 
  homology 
  of 
  the 
  parts 
  composing 
  this 
  duct 
  see 
  Beaun 
  

   (1894— 
  1900, 
  p. 
  1428-1431). 
  

  

  1) 
  Roboz 
  (1882) 
  questions 
  whether 
  these 
  are 
  actually 
  cilia 
  or 
  not. 
  

  

  