﻿INTERMEDIATE 
  BETWEEN 
  BIRDS 
  AND 
  REPTILES. 
  9 
  

  

  tainly 
  does 
  come 
  nearer 
  reptiles 
  than 
  the 
  others. 
  Those 
  are 
  the 
  

   llatitce, 
  or 
  Struthious 
  birds, 
  comprising 
  the 
  Ostrich, 
  Rhea, 
  Emu, 
  

   Cassowary, 
  Apteryoa, 
  and 
  the 
  but 
  recently 
  extinct 
  birds 
  of 
  New 
  

   Zealand, 
  the 
  Dinomithes, 
  which 
  attained 
  gigantic 
  dimensions. 
  All 
  

   these 
  birds 
  are 
  remarkable 
  for 
  the 
  small 
  size 
  of 
  their 
  wings, 
  the 
  

   absence 
  of 
  a 
  crest 
  or 
  keel 
  upon 
  the 
  breast-bone, 
  and 
  of 
  a 
  complete 
  

   furcula, 
  and, 
  in 
  many 
  cases, 
  for 
  the 
  late 
  union 
  of 
  the 
  bones 
  of 
  the 
  

   pinion, 
  the 
  foot, 
  and 
  the 
  skull. 
  In 
  this 
  last 
  character, 
  in 
  the 
  form 
  of 
  

   the 
  sternum, 
  of 
  the 
  shoulder-girdle, 
  and 
  in 
  some 
  peculiarities 
  of 
  the 
  

   skull, 
  these 
  birds 
  are 
  more 
  reptilian 
  than 
  the 
  rest 
  ; 
  but 
  the 
  total 
  

   amount 
  of 
  approximation 
  to 
  the 
  reptilian 
  type 
  is 
  but 
  small, 
  and 
  the 
  

   gap 
  between 
  reptiles 
  and 
  birds 
  is 
  but 
  very 
  slightly 
  narrowed 
  by 
  their 
  

   existence 
  " 
  *. 
  

  

  All 
  the 
  living, 
  or 
  recently 
  extinct, 
  wingless 
  birds, 
  however, 
  de- 
  

   serve 
  to 
  be 
  specially 
  mentioned, 
  not 
  only 
  on 
  account 
  of 
  the 
  more 
  

   generalized 
  type 
  of 
  structure 
  which 
  they 
  offer, 
  but 
  because 
  they 
  

   present, 
  in 
  their 
  distribution, 
  one 
  of 
  the 
  most 
  interesting 
  geogra- 
  

   phical 
  problems 
  to 
  the 
  consideration 
  of 
  naturalists 
  and 
  palaeonto- 
  

   logists. 
  

  

  Africa 
  has 
  its 
  Ostrich 
  f 
  ; 
  Madagascar 
  had 
  its 
  JEpyornis 
  ; 
  Java 
  

   and 
  the 
  adjacent 
  islands 
  of 
  the 
  Indian 
  archipelago 
  the 
  Cassowary 
  ; 
  

   Australia 
  its 
  Emu 
  and 
  extinct 
  Dromornis 
  % 
  ; 
  New 
  Zealand 
  its 
  

   Dinornis 
  ; 
  South 
  America 
  its 
  Rhea 
  ; 
  the 
  London 
  Clay 
  its 
  Dasornis 
  

   londiniensis§. 
  Thus, 
  then, 
  we 
  have 
  this 
  most 
  ancient 
  type 
  of 
  wing- 
  

   less 
  running 
  birds 
  presenting 
  not 
  merely 
  the 
  greatest 
  range 
  in 
  time, 
  

   but 
  also 
  the 
  widest 
  geographical 
  distribution 
  over 
  the 
  globe 
  of 
  any 
  

   order 
  .of 
  its 
  class. 
  None 
  of 
  these 
  forms, 
  however, 
  depart 
  in 
  the 
  main 
  

   from 
  the 
  avian 
  type, 
  and 
  we 
  must 
  seek 
  still 
  further 
  for 
  modifications 
  

   of 
  even 
  greater 
  import 
  than 
  the 
  wingless 
  birds 
  present. 
  

  

  Is 
  there 
  any 
  thing 
  in 
  the 
  Pterosauria 
  which 
  affords 
  a 
  missing 
  

   link 
  ? 
  

  

  If 
  we 
  examine 
  that 
  remarkable 
  group 
  the 
  " 
  flying 
  lizards," 
  or 
  

   Pterodactyl 
  es, 
  extending 
  in 
  time 
  from 
  the 
  Lias 
  to 
  the 
  Chalk, 
  we 
  

   find 
  they 
  exhibit 
  many 
  adaptive 
  modifications 
  of 
  the 
  avian 
  type, 
  such 
  

   as 
  the 
  great 
  air-cavities 
  in 
  the 
  bones, 
  and 
  the. 
  prolongation 
  of 
  the 
  

   prseruaxillse 
  into 
  beaks 
  (which 
  were 
  probably 
  sheathed 
  in 
  horn), 
  

   although 
  the 
  rest 
  of 
  the 
  jaw 
  was 
  armed 
  with 
  teeth. 
  But 
  the 
  manus, 
  

   with 
  its 
  four 
  free 
  digits 
  (three 
  armed 
  with 
  claws, 
  and 
  the 
  fourth 
  

   enormously 
  prolonged 
  to 
  support 
  the 
  wing 
  - 
  membrane), 
  the 
  non- 
  

   avian 
  characters 
  of 
  the 
  pelvis 
  and 
  hind 
  limbs, 
  all 
  depart 
  most 
  widely 
  

   from 
  the 
  ornithic 
  type. 
  

  

  But 
  among 
  the 
  various 
  additions 
  made 
  to 
  our 
  knowledge 
  of 
  ex- 
  

   tinct 
  forms, 
  some 
  at 
  least 
  may 
  certainly 
  be 
  claimed 
  as 
  affording 
  links 
  

  

  * 
  See 
  Huxley's 
  Lecture, 
  Geol. 
  Mag. 
  1868, 
  vol. 
  v. 
  p. 
  360. 
  

  

  t 
  Formerly 
  the 
  geographical 
  range 
  of 
  the 
  Ostrich 
  extended 
  into 
  Arabia, 
  Persia, 
  

   and 
  part 
  of 
  India, 
  within 
  the 
  Historic 
  period 
  ; 
  but 
  it 
  has 
  been 
  exterminated 
  by 
  

   the 
  agency 
  of 
  man. 
  

  

  { 
  Dromornis 
  australis, 
  Owen, 
  Trans. 
  Zool. 
  Soc. 
  1873, 
  vol. 
  viii. 
  part 
  vi., 
  and 
  

   Geol. 
  Mag. 
  1869, 
  vol. 
  vi. 
  p. 
  383. 
  

  

  § 
  See 
  Trans. 
  Zool. 
  Soc. 
  1872, 
  vol. 
  vii. 
  p. 
  123, 
  pi. 
  16. 
  This 
  specimen 
  was 
  de- 
  

   tected 
  and 
  its 
  avian 
  characters 
  pointed 
  out 
  by 
  Mr. 
  Davies, 
  of 
  the 
  British 
  Museum. 
  

  

  