﻿173 
  

  

  liabitants 
  ; 
  an 
  increased 
  percentage 
  means 
  a 
  decreased 
  popula- 
  

   tion. 
  

   I 
  It 
  is 
  evident 
  that 
  there 
  should 
  be 
  a 
  certain 
  proportion 
  be 
  

   tween 
  the 
  oysters 
  of 
  different 
  ages, 
  and 
  in 
  general 
  terms 
  the 
  

   number 
  of 
  young 
  should 
  exceed 
  the 
  mature, 
  thus 
  allowing 
  for 
  

   the 
  natural 
  depletion 
  in 
  each 
  period 
  of 
  growth. 
  

  

  Our 
  present 
  knowledge, 
  however, 
  is 
  not 
  sufficient 
  to 
  allow 
  

   the 
  assignment 
  of 
  exact 
  values 
  to 
  these 
  proportions, 
  and 
  the 
  

   ratios 
  between 
  the 
  different 
  classes 
  are 
  too 
  irregular, 
  owing 
  

   to 
  the 
  variations 
  in 
  the 
  spawnings 
  in 
  the 
  several 
  seasons, 
  to 
  

   allow 
  their 
  acceptance 
  as 
  a 
  standard. 
  

  

  One 
  thing, 
  however, 
  may 
  be 
  assumed 
  as 
  an 
  axiom, 
  and 
  that 
  

   is 
  that 
  the 
  number 
  of 
  young 
  growth 
  on 
  a 
  bed 
  should 
  always 
  

   exceed 
  the 
  mature 
  oysters, 
  for 
  if 
  there 
  are 
  no 
  young 
  oysters 
  

   in 
  the 
  community 
  there 
  will 
  soon 
  be 
  no 
  old 
  ones, 
  and 
  as 
  there 
  

   is 
  a 
  constant 
  depletion 
  of 
  each 
  class, 
  the 
  young 
  must 
  suffi- 
  

   ciently 
  outnumber 
  the 
  old 
  ones 
  to 
  allow 
  these 
  ravages 
  and 
  

   still 
  adequately 
  supply 
  the 
  demand 
  and 
  fill 
  up 
  the 
  vacant 
  

   places 
  in 
  the 
  higher 
  classes. 
  

  

  An 
  inspection 
  of 
  Table 
  1 
  will 
  show 
  — 
  ^ 
  

  

  1st. 
  That 
  0.75 
  per 
  cent, 
  of 
  the 
  4th 
  class 
  were 
  of 
  this 
  year's 
  

   growth. 
  

  

  2d. 
  That 
  the 
  ratios 
  between 
  the 
  3d 
  and 
  4tli 
  classes 
  are 
  the 
  

   largest, 
  and 
  between 
  the 
  2d 
  and 
  3d 
  classes 
  the 
  smallest. 
  

  

  As 
  the 
  2d 
  class 
  represents 
  oysters 
  of 
  between 
  two 
  and 
  three 
  

   years 
  of 
  age, 
  and, 
  as 
  the 
  ratio 
  between 
  the 
  2d 
  and 
  1st 
  classes 
  

   is 
  large, 
  I 
  judge 
  that 
  there 
  was 
  a 
  successful 
  spatting 
  on 
  these 
  

   beds 
  in 
  1876; 
  and 
  as 
  the 
  3d 
  class 
  represent, 
  on 
  the 
  whole, 
  

   oysters 
  of 
  the 
  season 
  of 
  1877 
  and 
  1878, 
  and 
  as 
  the 
  proportion 
  

   between 
  those 
  of 
  that 
  class 
  and 
  those 
  of 
  the 
  second 
  is 
  small, 
  

   I 
  infer 
  tliat 
  the 
  seasons 
  of 
  1877-78 
  were 
  bad 
  spawning 
  ones. 
  

   Again, 
  the 
  4th 
  class 
  are 
  principally 
  of 
  this 
  year's 
  growth, 
  

   and 
  the 
  ratio 
  of 
  4th 
  to 
  3d 
  class 
  is 
  large, 
  from 
  which 
  I 
  infer 
  

   what 
  was 
  the 
  case, 
  that 
  the 
  spatting 
  of 
  the 
  last 
  season 
  on 
  

   these 
  beds 
  was 
  successful. 
  

  

  As 
  already 
  explained, 
  the 
  3d 
  and 
  4th 
  classes 
  practically 
  rep- 
  

   resent 
  the 
  ofispring 
  of 
  three 
  successive 
  spatting 
  seasons, 
  and 
  

   thus 
  contain 
  the 
  young 
  growth 
  on 
  the 
  bed, 
  while 
  the 
  1st 
  and 
  

  

  