Front Matter
  I The Fundamental Principles of Genetics
  II Particulate Theories of Heredity
  III The Mechanism of Heredity
  IV Chromosomes and Genes
  V The Origin of Mutant Characters
  VI Are Mutant Recessive Genes Produced by Losses of Genes?
  VII The Location of Genes in Related Species
  VIII The Tetraploids, or Fourfold Type
  IX Triploids
  X Haploids
  XI Polyploid Series
  XII Heteroploids
  XIII Species Crossing and Changes in Chromosome Number
  XIV Sex and Genes
  XV Other Methods of Sex-Determination Involving the Sex Chromosomes
  XVI Intersexes
  XVII Sex Reversals
  XVIII Stability of the Gene
  IX General Conclusions