﻿222 
  

  

  Prof. 
  Carl 
  Chun 
  on 
  the 
  

  

  appearance 
  when 
  compared 
  with 
  the 
  astonishingly 
  rich 
  and 
  

   interesting 
  material 
  which 
  Hackel 
  had 
  at 
  his 
  disposal 
  in 
  the 
  

   Siphonophora 
  captured 
  by 
  the 
  ' 
  Challenger 
  ' 
  in 
  the 
  deep 
  sea 
  

   and 
  those 
  observed 
  by 
  himself 
  in 
  various 
  seas, 
  on 
  the 
  one 
  

   hand 
  I 
  hope 
  to 
  be 
  able 
  to 
  characterize 
  some 
  forms 
  which 
  may 
  

   claim 
  to 
  be 
  of 
  general 
  interest, 
  and 
  on 
  the 
  other 
  I 
  believe 
  I 
  

   have 
  here 
  and 
  there 
  also 
  enlarged 
  our 
  knowledge 
  of 
  the 
  post- 
  

   embryonal 
  development. 
  

  

  Dealing 
  in 
  

   the 
  first 
  place 
  

   with 
  the 
  lat- 
  

   ter 
  subject, 
  I 
  

  

  A 
  11/// 
  figure 
  here 
  a 
  

  

  developmen- 
  

   tal 
  stage 
  in 
  

   the 
  postem- 
  

   bryonal 
  evo- 
  

   lution 
  of 
  Hip- 
  

   p 
  o 
  p 
  odiu 
  s 
  

   which 
  may 
  

   serve 
  for 
  the 
  

   elucidation 
  of 
  

   the 
  above 
  re- 
  

   marks 
  upon 
  

   the 
  heteromorphous 
  primarynec- 
  

   tocalyces 
  of 
  the 
  Calycophoridas. 
  

   The 
  postembryonal 
  stages 
  of 
  

   HippopodtuSj 
  which 
  I 
  had 
  pre- 
  

   viously 
  observed 
  from 
  consider- 
  

   able 
  depths 
  in 
  the 
  Mediterranean, 
  

   I 
  have 
  succeeded 
  in 
  capturing 
  

   in 
  an 
  unbroken 
  series 
  at 
  the 
  

   surface 
  near 
  Orotava. 
  As 
  a 
  

   matter 
  of 
  course 
  I 
  directed 
  my 
  

   attention 
  particularly 
  to 
  those 
  

   rare 
  stages 
  in 
  which 
  both 
  hetero- 
  

   morphous 
  calyces 
  are 
  to 
  be 
  ob- 
  

   served 
  still 
  in 
  connexion. 
  By 
  

   very 
  careful 
  treatment 
  of 
  the 
  

   exceedingly 
  delicate 
  and 
  readily 
  

   separable 
  calyces 
  I 
  was 
  able 
  

   three 
  times 
  to 
  study 
  in 
  detail 
  the 
  

   stage 
  figured 
  under 
  the 
  micro- 
  

   scope. 
  The 
  primary 
  calyx 
  (A) 
  

   of 
  Hippopodius 
  luteus 
  is 
  of 
  a 
  

   general 
  ovate 
  form 
  and 
  presents 
  

  

  