﻿Reproductive 
  organs 
  of 
  Taenia 
  pisiformis. 
  381 
  

  

  ing 
  to 
  Eetzius 
  (1909) 
  the 
  spermatozoa 
  of 
  TetrarhyncJms 
  tetrabothrius 
  

   are 
  pointed 
  at 
  either 
  end, 
  the 
  more 
  pointed 
  being 
  probably 
  the 
  head 
  

   end. 
  Other 
  authors 
  however 
  describe 
  a 
  very 
  minute 
  body 
  at 
  one 
  

   end 
  of 
  the 
  sperm 
  which 
  may 
  represent 
  a 
  head. 
  Thus 
  Sommer 
  & 
  

   Landois 
  (1872, 
  p. 
  59) 
  describe 
  the 
  sperms 
  of 
  Bothriocephalus 
  latus 
  

   as 
  bearing 
  ". 
  . 
  . 
  ein 
  kleines, 
  stark 
  lichtbrechendes 
  Köpfchen". 
  Sommer 
  

   (1874, 
  p. 
  514) 
  speaks 
  of 
  those 
  of 
  Taenia 
  mediocanellafa 
  and 
  solium 
  

   as 
  possessing 
  ". 
  . 
  . 
  feine 
  glänzende 
  Köpfchen" 
  and 
  Roboz 
  (1882) 
  

   "finds 
  the 
  spermatozoa 
  of 
  SolenopJiorus 
  megalocephalus 
  furnished 
  with 
  

   a 
  spherical 
  sharply 
  refractive 
  head, 
  etc. 
  These 
  observations 
  render 
  

   uncertain 
  the 
  general 
  occurrence 
  of 
  a 
  well 
  differentiated 
  head 
  in 
  

   cestode 
  spermatozoa, 
  such 
  as 
  occurs 
  in 
  those 
  of 
  most 
  animals. 
  

  

  Cestode 
  spermatogenesis 
  has 
  received 
  brief 
  mention 
  from 
  several 
  

   authors, 
  but 
  their 
  accounts 
  vary 
  widely. 
  Thus 
  Moniez 
  (1881, 
  p. 
  57) 
  

   says 
  of 
  the 
  primitive 
  testis 
  cells 
  in 
  T. 
  cucumerina 
  "D'abord, 
  très 
  

   net, 
  le 
  noyau 
  finit 
  par 
  disparaître, 
  dissous 
  ou 
  caché 
  par 
  les 
  granules 
  

   . 
  . 
  . 
  suivi 
  brusquement 
  de 
  l'apparition, 
  à 
  l'intérieur 
  de 
  la 
  cellule 
  

   primitive 
  de 
  cellules-filles 
  relativement 
  nombreuses 
  nées 
  par 
  voie 
  

   endogène", 
  appearing 
  "plusieurs 
  à 
  la 
  fois". 
  These 
  give 
  rise 
  to 
  a 
  

   second 
  generation 
  of 
  cells 
  from 
  which 
  are 
  formed 
  the 
  sperms 
  by 
  a 
  

   process 
  of 
  elongation 
  and 
  reduction 
  of 
  the 
  head 
  until 
  it 
  becomes 
  

   extremely 
  small. 
  Meyner 
  (1895, 
  p. 
  31) 
  in 
  Taenia 
  ovilla 
  admits 
  his 
  

   inability 
  to 
  determine 
  "Ob 
  der 
  Kern 
  . 
  . 
  . 
  sich 
  in 
  Wirklichkeit 
  zum 
  

   Spermatozoenkopfe 
  verjüngt 
  . 
  . 
  ." 
  A 
  similar 
  doubt 
  is 
  expressed 
  

   by 
  Kahane 
  (1880) 
  regarding 
  T. 
  perfoliata, 
  while 
  in 
  Amphilina 
  

   Salensky 
  (1874) 
  claims 
  that 
  the 
  nucleus 
  plaj^s 
  no 
  part 
  in 
  sperm 
  

   formation. 
  Sommer 
  (1874) 
  in 
  Taenia 
  mediocanellata 
  and 
  solium 
  de- 
  

   scribes 
  the 
  "Bildungszellen" 
  of 
  the 
  spermatozoa 
  as 
  large 
  multinucleate 
  

   cells 
  (the 
  probable 
  equivalents 
  of 
  the 
  "cytophores" 
  of 
  Child 
  and 
  

   myself). 
  "An 
  der 
  Peripherie 
  dieser 
  grossen 
  Zellen 
  geht 
  von 
  irgend 
  

   einer 
  Stelle 
  die 
  Bildung 
  der 
  Samenfäden 
  aus. 
  Letztere 
  entstehen 
  

   lediglich 
  aus 
  dem 
  Protoplasma 
  der 
  Zelle; 
  eine 
  Betheiligung 
  der 
  Kerne 
  

   dabei 
  findet 
  nicht 
  statt" 
  (1. 
  c, 
  p. 
  514—515). 
  As 
  the 
  sperms 
  develop 
  

   the 
  protoplasm 
  of 
  these 
  "Bildungszellen" 
  disappears 
  and 
  their 
  in- 
  

   closed 
  nuclei 
  are 
  set 
  free, 
  later 
  degenerating 
  in 
  the 
  testes 
  or 
  passing 
  

   into 
  the 
  ducts 
  together 
  with 
  the 
  sperms. 
  A 
  similar 
  account 
  is 
  given 
  

   by 
  ZscHOKKE 
  (1888a) 
  for 
  Taenia 
  mamillana 
  and 
  relicta. 
  Kraemer 
  

   (1892) 
  in 
  Taenia 
  torulosa 
  and 
  Lönnberg 
  (1891) 
  in 
  Amphiptijches 
  urna, 
  

   on 
  the 
  other 
  hand, 
  attribute 
  the 
  sperm 
  head 
  to 
  the 
  nucleus, 
  and 
  the 
  

   tail 
  to 
  the 
  cytoplasm 
  of 
  the 
  sperm 
  forming 
  cells. 
  

  

  