﻿58 
  INTEODUCTION. 
  

  

  breediag 
  season 
  is 
  mentioned 
  in 
  the 
  chapter 
  on 
  

   pairing 
  and 
  ovi|)osition. 
  Ail 
  our 
  species 
  also 
  spend 
  a 
  

   certain 
  period 
  of 
  their 
  existence 
  as 
  gill-breathing, 
  

   fish-like 
  larvse 
  : 
  there 
  are 
  exceptional 
  forms 
  which 
  

   entirely 
  dispense 
  with 
  the 
  larval 
  life, 
  and 
  hop 
  out 
  of 
  

   the 
  egg 
  in 
  the 
  perfect 
  condition, 
  but 
  we 
  have 
  not 
  to 
  

   deal 
  with 
  them 
  here, 
  for 
  thej 
  are 
  only 
  found 
  between 
  

   the 
  tropics. 
  Even 
  our 
  most 
  aquatic 
  species 
  leave 
  the 
  

   water 
  after 
  metamorphosis, 
  and 
  young 
  specimens 
  of 
  

   Bana 
  esculenta 
  and 
  Bomhinator 
  are 
  terrestrial, 
  or 
  live 
  

   more 
  on 
  the 
  border 
  than 
  actually 
  in 
  the 
  water 
  until 
  

   able 
  to 
  breed. 
  Sexual 
  maturity 
  is 
  not 
  attained 
  before 
  

   the 
  third 
  or 
  fourth 
  year 
  in 
  males, 
  a 
  year 
  or 
  two 
  later 
  

   in 
  females 
  — 
  of 
  the 
  larger 
  species, 
  at 
  any 
  rate. 
  The 
  

   growth 
  is 
  slow, 
  and 
  so 
  prolonged 
  that 
  of 
  certain 
  species, 
  

   such 
  as 
  Bana 
  and 
  Bufo, 
  one 
  may 
  say 
  the 
  older 
  the 
  

   specimen 
  the 
  larger 
  ; 
  the 
  gigantic 
  size 
  attained 
  by 
  

   some 
  in 
  secluded 
  localities 
  appears 
  to 
  be 
  mainly 
  

   due 
  to 
  the 
  immunity 
  they 
  have 
  enjoyed 
  for 
  a 
  great 
  

   number 
  of 
  years. 
  Individuals 
  of 
  the 
  common 
  toad 
  

   have 
  been 
  observed 
  for 
  very 
  long 
  periods, 
  and 
  it 
  

   is 
  probably 
  no 
  exaggeration 
  to 
  assess 
  the 
  possible 
  

   duration 
  of 
  life 
  in 
  that 
  species 
  at 
  a 
  century. 
  Among 
  

   the 
  smaller 
  forms 
  a 
  tree-frog 
  has 
  been 
  kept 
  in 
  con- 
  

   finement 
  for 
  twenty-two 
  years. 
  

  

  The 
  food 
  consists 
  exclusively 
  of 
  live 
  prey 
  ; 
  no 
  

   insect 
  or 
  worm 
  will 
  be 
  taken 
  that 
  has 
  not 
  moved 
  in 
  

   the 
  presence 
  of 
  the 
  consumer. 
  But 
  it 
  is 
  easy 
  to 
  deceive 
  

   a 
  Batrachian 
  by 
  agitating 
  any 
  object 
  ; 
  the 
  edible 
  frog 
  is 
  

   thus 
  captured 
  in 
  France 
  by 
  means 
  of 
  a 
  red 
  rag 
  put 
  on 
  

   to 
  a 
  line. 
  In 
  fact, 
  any 
  moving 
  object 
  of 
  commensu- 
  

   rate 
  size 
  will 
  be 
  taken, 
  to 
  be 
  afterwards 
  rejected 
  if 
  dis- 
  

   tasteful. 
  Dlscoglossus 
  and 
  Bomhinator 
  alone 
  among 
  our 
  

   Batrachians 
  are 
  able 
  to 
  seize 
  their 
  prey 
  under 
  water. 
  

   The 
  thoroughly 
  nocturnal 
  forms 
  cannot 
  be 
  induced 
  

   to 
  feed 
  in 
  the 
  daytime. 
  Frogs 
  and 
  toads 
  occasionally 
  

   display 
  cannibal 
  instincts, 
  swallowing 
  young 
  of 
  their 
  

   own 
  species. 
  The 
  prey 
  is 
  secured 
  by 
  throwing 
  out 
  

   the 
  tongue, 
  except 
  in 
  the 
  Blscoglossldse, 
  which, 
  not 
  

  

  