﻿62 
  

  

  INTRODUCTION. 
  

  

  in 
  Bana, 
  or 
  slit-like, 
  and 
  situated 
  at 
  the 
  side 
  of 
  the 
  

   tongue, 
  as 
  in 
  most 
  other 
  genera. 
  Peloclytes 
  and 
  Hijla 
  

   have 
  two 
  openings, 
  whilst 
  Bufo 
  has 
  commonly 
  but 
  one, 
  

   either 
  on 
  the 
  right 
  side 
  or 
  on 
  the 
  left. 
  

  

  In 
  Bomhinator 
  igneii.s 
  internal 
  vocal 
  sacs 
  are 
  well 
  

   developed, 
  but 
  are 
  formed 
  by 
  the 
  skin 
  of 
  the 
  floor 
  of 
  

   the 
  mouth, 
  which 
  is 
  loose 
  and 
  plicate, 
  and 
  projects 
  

   through 
  a 
  slit 
  dividing 
  the 
  submaxillary 
  muscle 
  into 
  

   an 
  anterior 
  and 
  a 
  posterior 
  portion. 
  Discoglossiis 
  has 
  

   rudimentary 
  vocal 
  sacs 
  of 
  the 
  same 
  type, 
  but 
  they 
  are 
  

   confined 
  to 
  the 
  sides 
  of 
  the 
  throat, 
  near 
  the 
  mandible. 
  

   Bomhinator 
  loacliyinis, 
  Ah/tes, 
  Pelohates, 
  Bufo 
  viilgaris, 
  

   and 
  Bana 
  gvdeca, 
  latastu, 
  iberica, 
  and 
  agilis 
  lack 
  the 
  

   vocal 
  sacs. 
  

  

  The 
  mode 
  of 
  inflation 
  of 
  the 
  vocal 
  sac 
  is 
  best 
  

   observed 
  in 
  Hyla 
  arborea, 
  the 
  bladder-like 
  appendage 
  

   when 
  blown 
  being 
  of 
  enormous 
  size, 
  nearly 
  as 
  large 
  

   as 
  the 
  body, 
  which, 
  when 
  the 
  animal 
  croaks, 
  is 
  much 
  

  

  Fig. 
  24. 
  

  

  Hyla 
  arbor 
  ea, 
  ^, 
  with 
  the 
  vocal 
  sac 
  in 
  the 
  collapsed 
  and 
  inflated 
  

  

  conditions. 
  

  

  thinned 
  by 
  the 
  emptying 
  of 
  the 
  lungs, 
  as 
  shown 
  in 
  

   the 
  accompanying 
  figure 
  (Fig. 
  24). 
  This 
  mechanism 
  of 
  

   the 
  shifting 
  of 
  the 
  air 
  from 
  the 
  lungs 
  into 
  the 
  throat, 
  

   and 
  vice 
  versa, 
  explains 
  the 
  fact, 
  paradoxical 
  in 
  appear- 
  

   ance, 
  of 
  Batrachians 
  being 
  able 
  to 
  croak 
  under 
  water. 
  

   The 
  voice 
  varies 
  very 
  considerably 
  according 
  to 
  the 
  

   species, 
  and 
  the 
  names 
  bomhina, 
  sonans, 
  campanisona, 
  

   ridibunda, 
  cachinnans, 
  &c., 
  convey 
  the 
  impressions 
  

   made 
  on 
  the 
  ears 
  of 
  the 
  earlier 
  observers. 
  It 
  affords 
  

   the 
  trained 
  collector 
  one 
  of 
  the 
  surest 
  means 
  of 
  ascer- 
  

  

  