vi STUDIES IN THE EVOLUTION OF ANIMALS 



PAGE 



PART x, Explanation of the Callosities on the Legs of Equine Animals 



and others, . . . 229 



xi. The One Big Digit of the Horse, . . . . 241 



XII. Monstrosities as probable factors in the creation of species, . 273 



GENERAL CONCLUSIONS, . . . 325 



APPENDICES, . . 331 



