﻿RAN 
  A, 
  

  

  339 
  

  

  the 
  mud 
  under 
  water, 
  in 
  company 
  with 
  the 
  common 
  

   frog, 
  where 
  the 
  two 
  species 
  co- 
  exist. 
  

  

  Eggs. 
  — 
  Vitelline 
  sphere 
  measuring 
  2 
  to 
  2-J- 
  mm. 
  (up 
  

   to 
  3 
  according 
  to 
  Peracca), 
  blackish- 
  Drown 
  in 
  the 
  upper 
  

  

  Fig. 
  124. 
  

  

  half, 
  whitish 
  in 
  the 
  lower; 
  mucilaginous 
  envelop, 
  

   when 
  swollen 
  out, 
  measuring 
  9 
  to 
  12 
  mm. 
  The 
  eggs 
  

   form 
  a 
  single 
  lump, 
  smaller 
  as 
  a 
  rule 
  than 
  in 
  R. 
  tern- 
  

   jioraria, 
  and 
  do 
  not 
  float. 
  According 
  to 
  Heron-Royer 
  

   their 
  number 
  varies 
  between 
  669 
  and 
  1200. 
  I 
  have 
  

   myself 
  counted 
  1188 
  and 
  1415 
  in 
  broods 
  from 
  Turin. 
  

   The 
  embryo, 
  on 
  leaving 
  the 
  egg, 
  is 
  of 
  a 
  paler 
  brown 
  

   than 
  in 
  R. 
  temporaria, 
  and 
  its 
  external 
  gills 
  are 
  much 
  

   less 
  developed 
  and 
  unpigmented. 
  

  

  Tadpole 
  (PI. 
  Ill, 
  fig. 
  7). 
  — 
  In 
  general 
  form 
  similar 
  to 
  

   R. 
  esculenta, 
  but 
  snout 
  rather 
  shorter, 
  the 
  nostrils 
  being 
  

   equidistant 
  from 
  the 
  eyes 
  and 
  the 
  end 
  of 
  the 
  snout, 
  

   and 
  spiraculum 
  considerably 
  nearer 
  the 
  posterior 
  than 
  

   the 
  anterior 
  extremity 
  of 
  the 
  body. 
  Interocular 
  space 
  

   twice 
  as 
  great 
  as 
  the 
  distance 
  between 
  the 
  nostrils. 
  

   Tail 
  twice 
  to 
  twice 
  and 
  a 
  half 
  as 
  long 
  as 
  the 
  body, 
  

   pointed 
  and 
  attenuate 
  or 
  submucronate 
  at 
  the 
  end, 
  its 
  

   depth 
  about 
  twice 
  and 
  two 
  thirds 
  in 
  its 
  length 
  ; 
  upper 
  

  

  