﻿24 
  

  

  INTRODUCTION. 
  

  

  a 
  stripped 
  skin 
  held 
  against 
  the 
  ligbt, 
  gives 
  rise 
  to 
  the 
  

   yellow 
  vertebral 
  line 
  which 
  is 
  normal 
  in 
  Bufo 
  calamita, 
  

   and 
  only 
  exceptional 
  in 
  B. 
  viridis 
  and 
  vulgaris, 
  inde- 
  

   pendently 
  of 
  another 
  light 
  vertebral 
  streak 
  which 
  is 
  

   sometimes 
  also 
  present. 
  The 
  independence 
  of 
  the 
  

   two 
  is 
  most 
  conspicuous 
  in 
  cases 
  of 
  deviation 
  of 
  the 
  

   former, 
  as 
  often 
  happens 
  in 
  Biifo 
  calainita, 
  which 
  

   appears 
  to 
  be 
  caused 
  by 
  the 
  presence 
  of 
  large 
  glands 
  

   in 
  the 
  course 
  of 
  the 
  raphe 
  necessitating 
  a 
  winding 
  

   (Kg. 
  9). 
  

  

  Fig. 
  9. 
  

  

  Bvfo 
  calamita, 
  sbowing 
  yellow 
  raphe, 
  independent 
  of 
  light 
  

   vertebral 
  streak, 
  and 
  its 
  deviation 
  from 
  the 
  median 
  line 
  in 
  

   the 
  middle 
  of 
  the 
  back. 
  

  

  The 
  epidermis 
  is 
  remarkable 
  for 
  the 
  formation 
  of 
  

   horny 
  cells, 
  as 
  the 
  spines 
  on 
  the 
  warts 
  of 
  some 
  toads 
  

   and 
  Bomhinator 
  (Fig. 
  10, 
  p. 
  29), 
  or 
  the 
  sheaths 
  on 
  

   the 
  tips 
  of 
  the 
  digits 
  in 
  Biifo 
  and 
  Pelohates, 
  or 
  on 
  the 
  

   metatarsal 
  tubercles 
  when 
  these 
  are 
  much 
  developed. 
  

   There 
  are 
  also, 
  in 
  some 
  Batrachians, 
  special 
  small, 
  

   pearl-like 
  warts, 
  mostly 
  pigmentless, 
  the 
  " 
  tact-spots 
  " 
  

  

  