﻿454 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [28] 
  

  

  Die 
  erste 
  Erscheinnng 
  der 
  Schwanzfliigel 
  ist 
  namlich 
  in 
  der 
  Form 
  von 
  

   zarfcen 
  Hautlappen, 
  ganz 
  dicht 
  an 
  der 
  Spitze 
  des 
  Schwanzes, 
  in 
  eirier 
  

   bedeutenden 
  Entfernung 
  voin 
  After 
  und 
  Becken. 
  Dagegen 
  zeigeu 
  die 
  

   Schwanzfliigel 
  sich 
  in 
  ihrer 
  Entwickelung 
  ganz 
  analog 
  mit 
  der 
  Eticken- 
  

   flosse, 
  welche 
  selbst 
  eine 
  iu 
  der 
  Saugethierklasse 
  ganz 
  neue, 
  nur 
  den 
  

   Walithieren 
  znkommende 
  Form 
  der 
  Hautfaltung 
  ist." 
  

  

  As 
  I 
  bare 
  already 
  disposed 
  of 
  tiie 
  last 
  objection 
  raised 
  in 
  tbe 
  preced- 
  

   ing 
  quotation 
  as 
  to 
  tbe 
  dorsal 
  fin 
  which 
  this 
  author, 
  together 
  with 
  later 
  

   ones, 
  so 
  persistently 
  compares 
  with 
  the 
  flukes, 
  I 
  would 
  now 
  simply 
  call 
  

   attention 
  to 
  the 
  very 
  singular 
  dorsal 
  hump 
  filled 
  with 
  adipose 
  tissue 
  so 
  

   remarkably 
  developed 
  in 
  certain 
  races 
  of 
  the 
  zebu 
  or 
  Bos 
  indicus. 
  In 
  

   this 
  terrestrial 
  animal 
  the 
  dorsal 
  hump 
  has 
  as 
  much 
  right 
  to 
  be 
  called 
  

   a 
  fin 
  as 
  in 
  some 
  cetaceans. 
  And 
  it 
  is 
  but 
  a 
  step 
  from 
  the 
  dorsal 
  hum]) 
  

   of 
  the 
  zebu 
  to 
  the 
  one 
  or 
  two 
  dorsal 
  humps 
  found 
  in 
  the 
  existing 
  species 
  

   of 
  Camelus. 
  In 
  fact, 
  the 
  dorsal 
  fin 
  of 
  cetaceans 
  is 
  largely 
  tilled 
  with 
  

   adipose 
  matter, 
  as 
  in 
  these 
  terrestrial 
  forms, 
  though 
  of 
  course 
  it 
  would 
  

   be 
  pushing 
  the 
  reductio 
  ad 
  absurdum 
  argument 
  to 
  an 
  extreme 
  if 
  I 
  were 
  

   to 
  deny 
  that 
  the 
  dorsal 
  fin 
  of 
  Cetacea 
  is 
  not 
  different 
  in 
  function 
  from 
  

   the 
  adipose 
  bumps 
  of 
  terrestrial 
  Herbivora. 
  What 
  is 
  meant 
  here 
  is 
  

   that 
  the 
  similarity 
  or 
  likeness 
  existing 
  between 
  the 
  flukes 
  and 
  the 
  dor 
  

   .sal 
  tin 
  of 
  whales 
  and 
  porpoises, 
  is 
  delusive 
  and 
  is 
  merely 
  analogical, 
  

   and 
  that 
  the 
  argument 
  that 
  the 
  flukes 
  are 
  also 
  mere 
  integumentary 
  

   folds, 
  with 
  no 
  pbyletic 
  relation 
  to 
  hind 
  limbs, 
  is, 
  if 
  based 
  upon 
  nothing 
  

   more, 
  not 
  a 
  very 
  formidable 
  one, 
  especially 
  since 
  I 
  have 
  demonstrated 
  

   beyond 
  any 
  possible 
  doubt 
  that 
  a 
  limb 
  rudiment 
  may 
  be 
  and 
  is 
  trans 
  

   located 
  together 
  with 
  its 
  girdle 
  from 
  its 
  archaic 
  position 
  in 
  other 
  forms. 
  

   It 
  was 
  the 
  lack 
  of 
  a 
  knowledge 
  of 
  this 
  last 
  fact 
  that 
  might 
  well 
  induce 
  

   an 
  anatomist 
  to 
  hesitate 
  to 
  enunciate 
  the 
  doctrine 
  here 
  developed. 
  

  

  The 
  difficulty 
  in 
  regard 
  to 
  the 
  distance 
  {Entfernung) 
  or 
  hiatus 
  between 
  

   the 
  point 
  of 
  origin 
  of 
  the 
  flukes 
  and 
  the 
  anus 
  and 
  pelvis, 
  which 
  Es 
  

   chricht 
  very 
  properly 
  considers 
  important, 
  I 
  venture 
  to 
  think 
  has 
  been 
  

   quite 
  overcome 
  by 
  the 
  theory 
  of 
  inclusion, 
  which 
  we 
  may 
  say 
  now 
  really 
  

   assumes 
  the 
  dignity 
  of 
  a 
  theory 
  rather 
  than 
  that 
  of 
  a 
  hypothesis, 
  after 
  

   the 
  analysis 
  and 
  explication 
  of 
  the 
  facts 
  relating 
  to 
  the 
  structure 
  of 
  the 
  

   hind 
  limbs, 
  tail, 
  and 
  posterior 
  part 
  of 
  the 
  body 
  of 
  the 
  Phocidw 
  as 
  de- 
  

   veloped 
  iu 
  the 
  foregoing 
  pages. 
  

  

  3. 
  The 
  mammalian 
  foetus 
  nearly 
  always 
  has 
  the 
  head, 
  body, 
  and 
  tail 
  

   flexed 
  more 
  or 
  less, 
  so 
  that 
  the 
  bead 
  and 
  tail 
  arc 
  approximated 
  on 
  the 
  

   ventral 
  side 
  

  

  In 
  illustration 
  of 
  this, 
  see 
  Figs. 
  12 
  and 
  14, 
  the 
  first 
  representing 
  the 
  

   foetus 
  of 
  the 
  cat 
  and 
  the 
  latter 
  that 
  of 
  BelpMnapterus. 
  This 
  trait 
  seems 
  

   to 
  be 
  iu 
  part 
  inherited, 
  as 
  a 
  similar 
  flexure 
  of 
  the 
  embryo 
  occurs 
  in 
  large 
  

   yolked 
  Sauropsida, 
  but 
  is 
  obviously 
  in 
  part 
  also 
  due 
  to 
  confinement 
  of 
  

   the 
  growing 
  foetus 
  within 
  the 
  hollow 
  vesicular 
  chorion, 
  the 
  curvature 
  

   being 
  hence 
  more 
  or 
  less 
  mechanically 
  adaptive 
  in 
  conformity 
  with 
  the 
  

   curvature 
  of 
  the 
  walls 
  of 
  such 
  vesicle. 
  That 
  such 
  a 
  view 
  is 
  in 
  the 
  main 
  

  

  