﻿208 
  

  

  The 
  influence 
  of 
  increased 
  or 
  diminished 
  temperature 
  upon 
  

   the 
  formation 
  of 
  the 
  ova 
  and 
  spermatozoa 
  must 
  be 
  very 
  serious 
  

   and 
  very 
  considerable, 
  and, 
  judging 
  by 
  analogy, 
  it 
  would 
  seem 
  

   probable 
  that 
  the 
  formation 
  would 
  be 
  more 
  rapid 
  during 
  a 
  

   warm 
  spring 
  than 
  during 
  a 
  cold 
  one. 
  

  

  AVhether 
  the 
  formation 
  has 
  been 
  late 
  or 
  early 
  when 
  once 
  

   formed, 
  a 
  sudden 
  change 
  of 
  density 
  or 
  of 
  temperature 
  may 
  so 
  

   affect 
  the 
  oyster 
  or 
  the 
  generative 
  matter 
  that 
  the 
  latter 
  would 
  

   not 
  be 
  expelled, 
  and 
  only 
  upon 
  this 
  hypothesis 
  can 
  be 
  ex- 
  

   plained 
  the 
  retention 
  of 
  the 
  products 
  of 
  generation 
  noticed 
  in 
  

   so 
  many 
  oysters, 
  and 
  which 
  is 
  said 
  to 
  be 
  so 
  common, 
  for 
  none 
  

   of 
  the 
  other 
  conditions 
  are 
  subject 
  to 
  violent 
  changes, 
  such 
  

   being 
  peculiar 
  to 
  the 
  density 
  and 
  temperature 
  alone. 
  

  

  Prof. 
  Brooks 
  states 
  that 
  he 
  found 
  both 
  ova 
  and 
  spermatozoa 
  

   ripe 
  and 
  fit 
  for 
  fertilization 
  about 
  the 
  middle 
  of 
  May, 
  and 
  as 
  

   the 
  oysters 
  were 
  taken 
  from 
  shoal 
  water, 
  probably 
  one 
  fathom 
  

   deep, 
  the 
  shoal 
  water 
  oysters 
  were 
  probably 
  spawning 
  through- 
  

   out 
  June. 
  Both 
  Prof. 
  Brooks 
  and 
  myself 
  found 
  the 
  ripeness 
  

   of 
  the 
  oysters 
  to 
  depend 
  upon 
  the 
  depth 
  of 
  water 
  from 
  which 
  

   it 
  was 
  taken, 
  and 
  this 
  is 
  no 
  doubt 
  caused 
  by 
  the 
  ditlerence 
  of 
  

   temperatures. 
  

  

  Prof. 
  Brooks 
  also 
  states 
  that 
  there 
  was 
  a 
  great 
  deal 
  of 
  cold, 
  

   rainy 
  weather 
  during 
  June, 
  and 
  two 
  hail 
  storms. 
  The 
  rainy 
  

   weather 
  would 
  affect 
  the 
  density 
  of 
  the 
  water 
  by 
  increasing 
  

   the 
  volumes 
  of 
  the 
  various 
  creeks 
  and 
  rivers, 
  and 
  the 
  changes 
  

   of 
  density 
  would 
  probably 
  affect 
  the 
  production 
  and 
  emission 
  

   of 
  the 
  generative 
  matter. 
  

  

  It 
  is 
  an 
  interesting 
  coincidence 
  at 
  least, 
  that 
  the 
  oysters 
  found 
  

   to 
  be 
  fattening 
  with 
  the 
  products 
  of 
  generation 
  unexpelled 
  

   were 
  either 
  from 
  beds 
  in 
  comparatively 
  shoal 
  water 
  or 
  from 
  

   the 
  shoal 
  parts 
  of 
  deep 
  water 
  beds, 
  and 
  that 
  those 
  oysters 
  

   should 
  have 
  been 
  ripe 
  and 
  spawning 
  during 
  the 
  month 
  of 
  

   June. 
  Again, 
  it 
  may 
  be 
  that 
  the 
  lowness 
  of 
  the 
  temperature 
  

   prevented 
  the 
  deep 
  water 
  oysters 
  from 
  ripening 
  as 
  soon 
  as 
  

   usual, 
  and. 
  the 
  uiildness 
  of 
  the 
  succeeding 
  autumn 
  may 
  have 
  

   prevented 
  the 
  destruction 
  of 
  the 
  ova 
  and 
  spermatozoa, 
  thus 
  

   rendering 
  possible 
  the 
  fertilization 
  achieved 
  by 
  me 
  in 
  October. 
  

   The 
  oysters 
  from 
  which 
  I 
  procured 
  the 
  ova 
  and 
  spermatozoa 
  

   were 
  taken 
  from 
  deep 
  water. 
  

  

  