﻿Contents 
  xvii 
  

  

  LECTURE 
  PAGE 
  

  

  Purple 
  leaves. 
  Celosia. 
  Italian 
  poplar. 
  

   Cactus 
  dahlia. 
  Mutative 
  origin 
  of 
  Dah- 
  

   lia 
  fistulosa, 
  and 
  Geranium 
  pratense 
  in 
  

   the 
  experiment-garden. 
  

  

  XXII. 
  Systematic 
  atavism 
  630 
  

  

  Keappearance 
  of 
  ancestral 
  characters. 
  

   Primula 
  acaulis 
  umbellata. 
  Bracts 
  of 
  

   crucifers. 
  Zea 
  Mays 
  cryptosperma. 
  

   Equisetum, 
  Dipsacus 
  sylvestris 
  torsus. 
  

   Tomatoes. 
  

  

  * 
  

  

  XXIII. 
  Taxonomic 
  anomalies 
  658 
  

  

  Specific 
  characters 
  occurring 
  in 
  other 
  cases 
  

   as 
  casual 
  anomalies. 
  Papaver 
  brac- 
  

   teatum 
  monopetalum. 
  Desmodium 
  

   gyrans 
  and 
  monophyllous 
  varieties. 
  Pel- 
  

   tate 
  leaves 
  and 
  ascidia. 
  Flowers 
  on 
  

   leaves. 
  Leaves. 
  Hordeum 
  trifurcatum. 
  

  

  XXIV. 
  Hypothesis 
  of 
  periodical 
  mutations 
  . 
  . 
  686 
  

   Discovering 
  mutable 
  strains. 
  Periods 
  of 
  

   mutability 
  and 
  constancy. 
  Periods 
  of 
  

   mutations. 
  Genealogical 
  trees. 
  Limited 
  

   life-time 
  of 
  the 
  organic 
  kingdom. 
  

  

  F. 
  FLUCTUATIONS. 
  

  

  XXV. 
  General 
  laws 
  of 
  fluctuations 
  .... 
  715 
  

   Fluctuating 
  variability. 
  Quetelet's 
  law. 
  

   Individual 
  and 
  partial 
  fluctuations. 
  

   Linear 
  variability. 
  Influence 
  of 
  nutri- 
  

   tion. 
  Periodicity-curves. 
  

  

  XXVI. 
  Asexual 
  multiplication 
  of 
  extremes 
  . 
  . 
  742 
  

   Selection 
  between 
  species 
  and 
  intra-spe- 
  

   cific 
  selection. 
  Excluding 
  individual 
  

  

  