﻿VOICE. 
  63 
  

  

  taining 
  the 
  Batrachian 
  fauna 
  of 
  a 
  district 
  during 
  the 
  

   spring 
  and 
  early 
  summer 
  months 
  ; 
  for 
  although 
  it 
  

   may 
  not 
  lead 
  at 
  once 
  to 
  the 
  discovery 
  of 
  the 
  performer, 
  

   owing 
  to 
  his 
  most 
  deceptive 
  ventriloquial 
  accomplish- 
  

   ments, 
  the 
  whistling 
  argentine 
  note 
  of 
  Ahjtes 
  o.bstet- 
  

   ricans 
  (often 
  attributed 
  by 
  country 
  people 
  to 
  tlie 
  

   salamander), 
  the 
  hoo-hoo 
  of 
  Bomhinator 
  pacJiypns, 
  the 
  

   oonk'Oonh 
  of 
  Bomhinator 
  igneus, 
  the 
  creclc-crecJc-crech 
  

   of 
  Pelodytes, 
  the 
  dock-clock-cloch 
  of 
  Pelohates 
  fuscus, 
  a.re 
  

   so 
  characteristic 
  as 
  to 
  be 
  surely 
  recognised 
  by 
  whom- 
  

   soever 
  has 
  heard 
  them 
  before. 
  The 
  sound 
  uttered 
  

   by 
  the 
  breeding 
  Bufo 
  vulgaris 
  may 
  be 
  compared 
  to 
  a 
  

   feeble 
  oft-repeated 
  bark 
  ; 
  that 
  of 
  Rana 
  temporaria 
  may 
  

   be 
  rendered 
  by 
  grooJc, 
  grooh, 
  and 
  that 
  of 
  Rana 
  agilis 
  and 
  

   arvalis 
  by 
  co-co-co. 
  But 
  these 
  are 
  all 
  comparatively 
  

   feeble 
  monotonous 
  sounds. 
  If 
  we 
  turn 
  to 
  the 
  loud 
  

   croakers, 
  Rana 
  escnlenta, 
  Hyla 
  arborea, 
  and 
  Bvfo 
  

   calamita, 
  all 
  three 
  of 
  which 
  are 
  provided 
  with 
  external 
  

   vocal 
  sacs, 
  we 
  find 
  a 
  more 
  varied 
  performance, 
  which 
  

   when 
  produced 
  by 
  a 
  large 
  number 
  of 
  individuals, 
  as 
  is 
  

   usually 
  the 
  case, 
  is 
  simply 
  deafening, 
  and 
  audible 
  

   miles 
  away. 
  The 
  croaking 
  of 
  Rana 
  esculenta 
  has 
  been 
  

   admirably 
  rendered 
  by 
  Aristophanes 
  in 
  his 
  chorus 
  of 
  

   frogs, 
  Bpe/ceKf/ceS 
  Koa^ 
  Koa^. 
  Hyla 
  and 
  Biifo 
  calamita 
  are 
  

   more 
  difficult 
  to 
  imitate, 
  their 
  song 
  consisting 
  of 
  an 
  

   extremely 
  rapid 
  succession 
  of 
  highly 
  sonorous 
  vibrat- 
  

   ing 
  notes, 
  bra 
  or 
  era. 
  

  

  These 
  loud 
  vocalists 
  are 
  in 
  the 
  habit 
  of 
  joining 
  in 
  

   choruses, 
  ceasing 
  suddenly 
  at 
  the 
  approach 
  of 
  the 
  

   listener. 
  But 
  they 
  can 
  easily 
  be 
  induced 
  to 
  resume 
  

   the 
  concert 
  by 
  an 
  imitation 
  of 
  their 
  croak 
  either 
  by 
  

   the 
  human 
  voice 
  or 
  by 
  strokes 
  on 
  a 
  metal 
  object. 
  In 
  

   confinement 
  they 
  can 
  also 
  be 
  enticed 
  to 
  croak 
  by 
  

   being 
  rubbed 
  on 
  the 
  back. 
  

  

  Most 
  frogs 
  when 
  seized 
  by 
  a 
  snake 
  or 
  other 
  enemy 
  

   utter 
  a 
  shrill 
  cry. 
  That 
  of 
  Pelobates 
  fuscus 
  is 
  most 
  

   startling 
  ; 
  and 
  specimens 
  of 
  that 
  species, 
  when 
  per- 
  

   sistently 
  teased, 
  can 
  be 
  aroused 
  to 
  a 
  fit 
  of 
  anger, 
  

   accompanied 
  by 
  loud 
  cries, 
  lasting 
  for 
  several 
  minutes. 
  

  

  