﻿114 
  INTRODUCTION. 
  

  

  by 
  V. 
  Mehely 
  that, 
  in 
  the 
  few 
  localities 
  wliere 
  the 
  two 
  

   species 
  co-exist, 
  intermediate 
  specimens 
  occur 
  w^hich 
  

   are 
  no 
  doubt 
  to 
  be 
  regarded 
  as 
  hybrids. 
  

  

  As 
  to 
  the 
  supposed 
  hybrids 
  between 
  Bana 
  esculenta 
  

   and 
  temporaria^ 
  noticed 
  by 
  Schlotthauber 
  and 
  others, 
  

   they 
  are 
  nothing 
  but 
  U. 
  arvalis, 
  a 
  species 
  which 
  is 
  in 
  

   many 
  respects 
  intermediate 
  between 
  the 
  two 
  supposed 
  

   parents, 
  and 
  with 
  which 
  the 
  authors 
  in 
  question 
  do 
  

   not 
  seem 
  to 
  have 
  been 
  well 
  acquainted. 
  

  

  Hybrid 
  embryos 
  between 
  Rana 
  esculenta 
  and 
  R. 
  

   arvalis 
  appear 
  to 
  have 
  been 
  recently 
  obtained 
  by 
  W. 
  

   Gebhardt. 
  

  

  So-called 
  hybrids 
  between 
  Hijla 
  arbor 
  ea 
  and 
  H. 
  

   meridionaUs 
  (haryfonus), 
  and 
  Biifo 
  viridis 
  and 
  B. 
  

   arahlcns, 
  obtained 
  by 
  Heron-Koyer, 
  are 
  only 
  mongrels, 
  

   as 
  I 
  do 
  not 
  consider 
  the 
  specific 
  distinctions 
  justified. 
  

  

  