XIV CONTENTS. 



CHAPTER PAGE 



XIX. CoLOUBE OP Flowers ... ... ... ... 174 



V XX. The Emergence op the Floral Whobls ... 184 



XXI. The Detelopment op the Floral Whorls ...' 191 



XXII. Heterogamy and Autogamy ... ... ... 198 



XXIII. Hbterostyusm ... ... ... ... ... 203 



XXrV. Partial Dicldiism ... ... ... ... 220 



XXV. Sexuality and the Ehvirokment... ... ... 230 



XXVI. Degeneracy op Flowers ... ... ... 251 



XXVn. Degeneracy op Flowers — CorUimied ... ... 273 



XXVIU. Pbogresbite Metamorphoses ... ... ... 285 



XXIX. Eetrogresstve Metamorphoses ... ... ... 295 



XXX. Phyllody of the Floral Whorls ... ... 301 



XXXI. The Varieties or Fertilisation ... ... ... 311 



XXXII. Fertilisation and the Origin op Species .:. 329 



