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  KANID/l-:. 
  

  

  water. 
  In 
  Germany 
  the 
  larvae 
  transform 
  between 
  

   the 
  middle 
  of 
  June 
  and 
  the 
  beginning 
  of 
  August. 
  

  

  In 
  spite 
  of 
  what 
  the 
  great 
  development 
  of 
  the 
  meta- 
  

   tarsal 
  tubercle 
  would 
  seem 
  to 
  indicate, 
  this 
  frog 
  cannot 
  

   be 
  said 
  to 
  show 
  any 
  special 
  disposition 
  to 
  burrow 
  ; 
  and 
  

   as 
  far 
  as 
  my 
  experience 
  goes, 
  from 
  having 
  repeatedly 
  

   kept 
  individuals 
  in 
  confinement, 
  it 
  does 
  not 
  seem 
  in 
  

   any 
  way 
  to 
  excel 
  the 
  common 
  species 
  in 
  this 
  respect. 
  

   The 
  physiological 
  significance 
  of 
  the 
  character 
  is 
  no 
  

   more 
  obvious 
  here 
  than 
  in 
  those 
  varieties 
  of 
  liana 
  

   esculenta 
  in 
  which 
  the 
  metatarsal 
  tubercle 
  attains 
  so 
  

   great 
  a 
  development, 
  without 
  yet 
  the 
  frogs 
  differing 
  

   appreciably 
  in 
  their 
  mode 
  of 
  life 
  from 
  their 
  spurless 
  

   allies. 
  

  

  Fig. 
  106. 
  

  

  Male 
  and 
  female 
  pairing. 
  

  

  Hybrids 
  between 
  this 
  species 
  and 
  B. 
  temporaria 
  

   have 
  been 
  obtained 
  with 
  great 
  difficulty 
  by 
  Born, 
  

   the 
  latter 
  species 
  acting 
  as 
  the 
  male, 
  whilst 
  all 
  

   attempts 
  at 
  reciprocal 
  crossing 
  have 
  hitherto 
  failed. 
  

  

  Eggs. 
  — 
  Intermediate 
  in 
  appearance 
  between 
  those 
  of 
  

   B. 
  esculenta, 
  and 
  B. 
  temporaria, 
  the 
  vitellus 
  measuring 
  

   1-J 
  to 
  2 
  mm. 
  in 
  diameter, 
  and 
  the 
  mucilaginous 
  envelop, 
  

  

  