﻿72 
  INTEODTJOTION. 
  

  

  fingers, 
  on 
  the 
  chin, 
  the 
  belly, 
  and 
  on 
  the 
  free 
  

   edge 
  of 
  the 
  web 
  between 
  the 
  toes 
  (Fig. 
  27, 
  a). 
  

  

  Discoglossus. 
  

  

  On 
  the 
  inner 
  side 
  of 
  the 
  three 
  inner 
  fingers 
  and 
  

  

  the 
  antebrachium, 
  and 
  on 
  the 
  third, 
  the 
  second 
  

  

  and 
  third, 
  or 
  the 
  second, 
  third, 
  and 
  fourth 
  toes 
  

  

  (Fig. 
  27, 
  c) 
  . 
  . 
  BomhmatoT 
  pachypus. 
  

  

  On 
  the 
  inner 
  side 
  of 
  the 
  two 
  inner 
  fingers 
  and 
  the 
  

  

  antebrachium 
  . 
  . 
  Bombinator 
  igneus. 
  

  

  On 
  the 
  inner 
  side 
  of 
  the 
  three 
  inner 
  fingers 
  

  

  (Fig. 
  27, 
  d) 
  Bufo, 
  

  

  On 
  the 
  inner 
  and 
  upper 
  side 
  of 
  the 
  inner 
  finger 
  

  

  (Fig. 
  27, 
  e) 
  Uana, 
  

  

  At 
  the 
  base 
  of 
  the 
  inner 
  finger 
  . 
  . 
  JSyla. 
  

  

  It 
  sometimes 
  happens 
  that 
  old 
  females 
  present 
  at 
  

   least 
  traces 
  of 
  these 
  organs, 
  the 
  appanage 
  of 
  the 
  males. 
  

   I 
  have 
  recorded 
  such 
  a 
  case 
  in 
  a 
  Rana 
  temporaria 
  with 
  

   eggs 
  in 
  the 
  oviducts 
  ; 
  Bosca 
  has 
  found 
  the 
  same 
  

   anomaly 
  in 
  a 
  Pelodytes 
  punctatus, 
  and 
  Mehely 
  in 
  five 
  

   specimens 
  of 
  Bombinator 
  pachypus. 
  These 
  horny 
  

   productions 
  are 
  usually 
  dark 
  brown 
  or 
  black; 
  they 
  

   are 
  greyish 
  in 
  Rana 
  esculenta 
  and 
  agilis, 
  colourless 
  

   in 
  Hyla 
  arborea. 
  Their 
  aspect 
  under 
  the 
  microscope, 
  

   and 
  the 
  difi'erences 
  they 
  present 
  according 
  to 
  the 
  

   species, 
  have 
  been 
  studied 
  by 
  Lataste, 
  who 
  has 
  shown 
  

   that 
  they 
  are 
  low 
  and 
  obtuse 
  in 
  Rana 
  esculenta 
  and 
  

   agilis, 
  erect 
  and 
  pointed 
  in 
  Ra.na 
  temporaria 
  and 
  arvalis 
  

   and 
  Discoglossus, 
  pointed 
  and 
  oblique 
  or 
  hooked 
  in 
  

   Bombinator 
  and 
  Pelodytes, 
  pointed, 
  erect, 
  and 
  crenu- 
  

   lated 
  in 
  Bufo 
  vulgaris 
  and 
  viridis, 
  and 
  obtuse 
  and 
  

   crenulated 
  in 
  Bufo 
  calamita 
  (Fig. 
  28). 
  

  

  As 
  in 
  all 
  Batrachians 
  in 
  which 
  no 
  courtship 
  takes 
  

   place, 
  the 
  males 
  are 
  not 
  distinguished 
  by 
  any 
  orna- 
  

   mental 
  appendages 
  or 
  more 
  vivid 
  colours, 
  but 
  in 
  Rana 
  

   temporaria 
  and 
  arvalis 
  they 
  acquire 
  during 
  the 
  pairing 
  

   season 
  a 
  peculiar 
  swelling 
  of 
  the 
  skin, 
  by 
  which 
  the 
  

   back, 
  and 
  especially 
  the 
  gular 
  region, 
  take 
  on 
  a 
  bluish 
  

   tinge 
  and 
  a 
  flabby 
  texture, 
  strongly 
  contrasting 
  with 
  

   the 
  aspect 
  of 
  the 
  same 
  parts 
  later 
  in 
  the 
  year. 
  The 
  

  

  