1963 ed. published under title: Animal species and evolution
Includes bibliographical references (pages 427-444)
Evolutionary biology -- Species concepts and their application -- Morphological species characters and sibling species -- Biological properties of species -- Isolating mechanisms -- The breakdown of isolating mechanisms (Hybridization) -- The population, its variation and genetics -- Factors reducing the genetic variation of populations -- Storage and protection of genetic variation -- The unity of the genotype -- Geographic variation -- The polytypic species of the taxonomist -- The population structure of species -- Kinds of species -- Multiplication of species -- Geographic speciation -- The genetics of speciation -- The ecology of speciation -- Species and transpecific evolution -- Man as a biological species -- Glossary
Cut-off text on some pages due text runs into the gutter.