﻿VISCERA. 
  55 
  

  

  large 
  calibre 
  and 
  tapers 
  gradually 
  towards 
  the 
  cloaca. 
  

   R. 
  temporaria 
  has 
  larger 
  testes, 
  measuring 
  two-thirds 
  

   to 
  three-fourths 
  the 
  length 
  of 
  the 
  kidneys, 
  nearer 
  the 
  

   anterior 
  than 
  the 
  posterior 
  extremity 
  of 
  the 
  latter, 
  and 
  

   often 
  more 
  or 
  less 
  strongly 
  pigmented 
  ; 
  the 
  vesicula 
  

   seminis 
  is 
  large 
  and 
  distinct 
  from 
  the 
  ureter, 
  im- 
  

   mediately 
  behind 
  the 
  kidney. 
  In 
  R, 
  arvalis, 
  R. 
  grseca, 
  

   R. 
  latastii, 
  and 
  R. 
  agilis 
  the 
  testes 
  are, 
  as 
  a 
  rule, 
  

   smaller, 
  one-third 
  to 
  two-thirds 
  the 
  length 
  of 
  the 
  

   kidneys, 
  and 
  not 
  or 
  but 
  feebly 
  pigmented. 
  In 
  

   R. 
  temporaria, 
  grdeca, 
  latastii, 
  the 
  vesicula 
  seminis 
  is 
  

   in 
  contact 
  with 
  the 
  kidney, 
  whilst 
  in 
  R. 
  arvalis 
  and 
  

   R, 
  agilis 
  it 
  is 
  a 
  small 
  sac, 
  usually 
  situated 
  along 
  the 
  

   ureter 
  midway 
  between 
  its 
  attachment 
  to 
  the 
  kidney 
  

   and 
  the 
  cloaca. 
  I 
  have, 
  however, 
  dissected 
  specimens 
  

   of 
  Rana 
  arvalis 
  in 
  which 
  the 
  vesicle 
  was 
  situated 
  

   very 
  near 
  the 
  kidney. 
  

  

  The 
  chief 
  differences 
  in 
  the 
  male 
  urogenital 
  appa- 
  

   ratus 
  may 
  be 
  expressed 
  in 
  the 
  following 
  synopsis 
  : 
  

  

  I. 
  The 
  spermatozoa 
  are 
  conveyed 
  through 
  the 
  vasa 
  

  

  efferentia 
  direct 
  to 
  the 
  seminal 
  duct; 
  the 
  latter 
  

   produced 
  forwards 
  beyond 
  the 
  kidney. 
  

  

  DiSCOGLOSSIDiE. 
  

  

  A. 
  The 
  ureter 
  functions 
  as 
  seminal 
  duct. 
  

   A 
  single 
  vas 
  efferens 
  ; 
  a 
  vesicula 
  seminis. 
  

  

  Dlscoglossus. 
  

  

  Several 
  vasa 
  efferentia 
  opening 
  into 
  a 
  canal 
  along 
  

  

  the 
  outer 
  edge 
  of 
  the 
  kidney 
  ; 
  no 
  vesicula 
  

  

  seminis 
  ..... 
  Bomhinator. 
  

  

  B. 
  The 
  Miillerian 
  duct 
  functions 
  as 
  seminal 
  canal 
  

  

  distinct 
  from 
  the 
  ureter 
  ; 
  two 
  vasa 
  efferentia 
  

   close 
  together 
  in 
  front 
  of 
  the 
  kidne}^ 
  ; 
  a 
  

   vesicula 
  seminis 
  .... 
  Alytes, 
  

  

  II. 
  The 
  spermatozoa 
  are 
  conveyed 
  to 
  the 
  seminal 
  

  

  duct 
  (ureter) 
  through 
  the 
  kidney, 
  in 
  which 
  the 
  

   anterior 
  extremity 
  of 
  the 
  duct 
  is 
  embedded. 
  

  

  