﻿15 
  

  

  The 
  generative 
  organs 
  of 
  the 
  oyster, 
  Gen. 
  Fig. 
  2, 
  are 
  

   massive 
  in 
  proportion 
  to 
  the 
  size 
  of 
  the 
  animal 
  ; 
  they 
  

   invest 
  the 
  whole 
  of 
  the 
  visceral 
  mass 
  from 
  a 
  little 
  be- 
  

   hind 
  the 
  palps 
  to 
  the 
  pericardial 
  space, 
  extending 
  beyond 
  

   it 
  posteriorly 
  above 
  and 
  below. 
  They 
  invest 
  the 
  rectum 
  to 
  

   within 
  a 
  short 
  distance 
  of 
  the 
  vent 
  and 
  the 
  first 
  bend 
  of 
  

   the 
  intestine 
  below 
  the 
  adductor 
  muscle; 
  their 
  substance 
  

   also 
  dips 
  down 
  dee^j 
  amongst 
  the 
  viscera 
  so 
  as 
  to 
  appear 
  

   to 
  cover 
  the 
  intestines, 
  the 
  pouch 
  of 
  the 
  crystalline 
  style 
  

   and 
  the 
  liver. 
  The 
  sexes 
  of 
  the 
  oyster 
  are 
  distinct, 
  but 
  

  

  Figure 
  2. 
  

   there 
  i8 
  no 
  apparent 
  possibility 
  of 
  determining 
  the 
  sexes 
  

   from 
  the 
  external 
  appearance 
  of 
  the 
  generative 
  tissues, 
  

   since 
  there 
  seem 
  to 
  be 
  no 
  differences 
  between 
  what 
  in 
  

   one 
  case 
  are 
  ovaries 
  containing 
  eggs, 
  and 
  in 
  another 
  

   spermaries 
  or 
  testes, 
  containing 
  the 
  male 
  cells 
  or 
  sperm- 
  

   atozoa. 
  Both 
  kinds 
  of 
  glands 
  are 
  composed 
  of 
  a 
  great 
  

   number 
  of 
  tubular 
  branches 
  which 
  unite 
  into 
  two 
  large 
  

   canals, 
  one 
  on 
  each 
  side 
  of 
  the 
  body, 
  which 
  open 
  * 
  into 
  

   thr 
  ui^per 
  gill 
  cavity 
  at 
  off 
  ; 
  the 
  oviducts 
  if 
  the 
  specimen 
  

   be 
  female, 
  and 
  casa 
  deferentia 
  if 
  the 
  specimen 
  be 
  a 
  male. 
  

   The 
  smaller 
  branches 
  divide 
  and 
  subdivide, 
  as 
  may 
  be 
  

   noted 
  in 
  Fig. 
  2, 
  giving 
  off 
  ultimately 
  short 
  blind, 
  pouch- 
  

   like 
  branches, 
  which 
  are 
  the 
  follicles 
  of 
  the 
  glands 
  or 
  

  

  