﻿" 
  Rogues" 
  among 
  Culinary 
  Peas 
  (Pisum 
  sativum). 
  193 
  

  

  Since 
  plants 
  can 
  be 
  found 
  giving 
  every 
  proportion 
  of 
  non-pointed 
  to 
  

   pointed, 
  the 
  actual 
  ratios 
  observed 
  in 
  any 
  group 
  of 
  plants 
  mean 
  little 
  unless 
  

   the 
  group 
  can 
  be 
  accurately 
  defined. 
  Such 
  definition 
  on 
  somatic 
  characters 
  

   is 
  not 
  strictly 
  possible. 
  In 
  choosing 
  plants 
  for 
  crossing, 
  we 
  took 
  those 
  which,, 
  

   judged 
  on 
  their 
  early 
  stages, 
  might 
  be 
  expected 
  to 
  throw 
  a 
  small 
  minority 
  of 
  

   non-pointed 
  plants, 
  for 
  our 
  object 
  was 
  to 
  examine 
  the 
  gradational 
  effect, 
  

   which 
  can 
  only 
  be 
  manifested 
  by 
  plants 
  of 
  that 
  composition. 
  In 
  Table 
  II, 
  

   however, 
  we 
  have 
  plants 
  chosen 
  when 
  ripening, 
  on 
  their 
  adult 
  characters, 
  

   selected 
  further 
  on 
  account 
  of 
  their 
  being 
  well 
  grown, 
  and 
  the 
  result 
  is 
  that 
  

   these, 
  as 
  tested 
  by 
  their 
  offspring, 
  proved 
  to 
  be 
  of 
  a 
  somewhat 
  higher 
  con-, 
  

   stitution 
  than 
  those 
  chosen 
  for 
  crossing. 
  For 
  any 
  plants 
  which 
  did 
  

   eventually 
  show 
  the 
  rogue 
  " 
  points 
  " 
  are 
  not 
  too 
  high 
  to 
  show 
  the 
  gradational 
  

   effect, 
  though 
  judged 
  as 
  young 
  plants, 
  before 
  they 
  had 
  assumed 
  the 
  points, 
  

   they 
  would 
  not 
  have 
  been 
  known 
  to 
  be 
  available 
  for 
  the 
  purposes 
  for 
  which 
  

   the 
  crosses 
  were 
  made. 
  The 
  higher 
  the 
  level 
  at 
  which 
  the 
  points 
  appear, 
  on 
  

   the 
  whole, 
  the 
  higher 
  is 
  the 
  proportion 
  of 
  non-pointed 
  plants 
  found 
  among 
  

   the 
  offspring, 
  but 
  this 
  correspondence 
  is 
  rough, 
  and 
  only 
  becomes 
  apparent 
  

   when 
  long 
  series 
  of 
  families 
  are 
  examined. 
  

  

  Recapitula 
  Hon. 
  

   The 
  three 
  chief 
  phenomena 
  may 
  be 
  recapitulated 
  : 
  — 
  

  

  1. 
  Reciprocal 
  crosses 
  between 
  type 
  and 
  rogue 
  give 
  plants 
  which, 
  as 
  they 
  

   develop, 
  turn 
  into 
  rogues. 
  

  

  2. 
  Though 
  the 
  characters 
  of 
  the 
  type 
  are 
  certainly 
  introduced, 
  manifesting 
  

   their 
  presence 
  by 
  affecting 
  the 
  form 
  of 
  the 
  young 
  Fi 
  plant, 
  they 
  very 
  rarely* 
  

   take 
  part 
  in 
  the 
  germ-lineage, 
  being 
  apparently 
  left 
  behind 
  in 
  the 
  lower 
  nodes. 
  

  

  3. 
  Plants 
  really 
  intermediate 
  between 
  type 
  and 
  rogue 
  nevertheless 
  exist, 
  

   but 
  never 
  breed 
  even 
  approximately 
  true. 
  Their 
  germ-cells 
  may 
  be 
  either 
  

   type, 
  intermediate 
  (of 
  at 
  least 
  two 
  kinds), 
  or 
  rogue. 
  The 
  proportion 
  of 
  

   gametes 
  carrying 
  type-characters 
  is 
  different 
  on 
  the 
  male 
  and 
  female 
  sides. 
  

   In 
  both 
  sexes 
  the 
  ratio 
  shows 
  gradational 
  change. 
  

  

  Of 
  the 
  egg-cells 
  of 
  the 
  lower 
  flowers, 
  up 
  to 
  about 
  the 
  10th 
  flowering 
  node, 
  

   rather 
  more 
  than 
  50 
  per 
  cent, 
  carry 
  the 
  type-characters 
  — 
  or, 
  at 
  least, 
  the 
  

   non-pointed 
  character 
  — 
  above 
  which 
  level 
  the 
  proportion 
  declines. 
  

  

  Of 
  the 
  pollen 
  in 
  the 
  lowest 
  two 
  flowers, 
  only 
  about 
  20 
  per 
  cent, 
  is 
  type- 
  

   bearing, 
  and 
  the 
  proportion 
  diminishes 
  rapidly 
  in 
  each 
  successive 
  flower 
  

   above 
  this 
  level. 
  

  

  * 
  The 
  exceptions 
  mentioned 
  in 
  our 
  first 
  paper 
  ('Jour. 
  Genetics,' 
  vol. 
  5, 
  pp. 
  29-30, 
  

   1915), 
  should 
  probably 
  be 
  thus 
  interpreted. 
  A 
  few 
  others 
  have 
  since 
  been 
  met 
  with 
  

   which 
  hereafter 
  will 
  need 
  detailed 
  description. 
  

  

  