﻿TADPOLES. 
  

  

  103 
  

  

  opens 
  on 
  the 
  left 
  side, 
  straight 
  backwards 
  in 
  Bufo, 
  

   backwards 
  and 
  upwards 
  in 
  the 
  other 
  genera 
  (Fig. 
  45, 
  

   B, 
  sp. 
  ; 
  Fig. 
  46, 
  A, 
  b). 
  

  

  Fig. 
  45. 
  

  

  sp. 
  

  

  an. 
  

  

  Lower 
  view 
  of 
  tadpoles 
  of 
  — 
  a. 
  Alytes 
  ohstetricans. 
  

  

  (From 
  'P. 
  Z. 
  S./ 
  1891.) 
  

  

  B. 
  Hyla 
  arhorea. 
  

  

  The 
  Lines 
  of 
  Muciferous 
  Orypts 
  or 
  Sensory 
  Canals. 
  — 
  

   All 
  tadpoles 
  are 
  provided 
  with 
  these 
  organs, 
  the 
  homo- 
  

   logues 
  of 
  the 
  lateral 
  line 
  in 
  fishes 
  ; 
  they 
  stand 
  in 
  imme- 
  

   diate 
  relation 
  to 
  the 
  nerve 
  branches, 
  and 
  are 
  regarded 
  

   as 
  organs 
  of 
  a 
  special 
  sense 
  possessed 
  by 
  aquatic 
  

   animals, 
  feeling, 
  in 
  its 
  broadest 
  sense, 
  having 
  been 
  

   admitted 
  as 
  their 
  possible 
  use, 
  and 
  the 
  function 
  of 
  

   determining 
  waves 
  of 
  vibration 
  in 
  the 
  aqueous 
  medium 
  

   having 
  been 
  suggested. 
  The 
  surface 
  openings 
  of 
  these 
  

   tubules 
  or 
  canals 
  form 
  lines 
  which 
  may 
  differ 
  greatly 
  

  

  