CONTENTS. xxiii 



fertile — Oxalis, transmission of form to the legitimate and 

 illegitimate seedlings — Primula Sinensis, illegitimate offspring 

 in some degree dwarfed and infertile — Bqnal-styled varieties 

 of P. Sinensis, auricula, farinosa, and elatior — P. Tulgaris, 

 red-flowered variety, illegitimate seedlings sterile — P. veris, 

 illegitimate plants raised during several successive genera- 

 tions, their dwarfed stature and sterility — Equal-styled varie- 

 ties of P. veris — Transmission of form by Pulmonaria and 

 Polygonum — Concluding remarks — Close parallelism between 

 illegitimate fertilisation and hybridism . . Page 188-244 



CHAPTER VI. 



CoNCLuoiira Remakks on Heterosttled Plants. 



The essential character of heterostyled plants — Summary of the 

 differences in fertility between legitimately and illegitimately 

 fertilised plants — Diameter of the pollen-grains, size of an- 

 thers and structure of stigma in the different forms — Affinities 

 of the genera which include heterostyled species — Nature of 

 the advantages derived from heterostylism — The means by 

 which plants become heterostyled — Transmission of form 

 — Equal-styled varieties of heterostyled plants — Pinal re- 

 marks 245-277 



CHAPTER VII. 



POLTOAMOUS, DiCECIOUS, AND GyNO-DI<ECIOUS PIiANTS, 



The conversion in various ways of hermaphrodite into dioecious 

 plants — Heterostyled plants rendered dioecious — Rubiaceaa — 

 Verbenaceae — Polygamous and sub-dioecious plants — Euo- 

 nymus — Fragaria — The two sub-forms of both sexes of Rham- 

 nus and Epigaea — Ilex — Gyno-dioecious plants — Thymus, dif- 

 ference in fertility of the hermaphrodite and female individuals 

 — Satureia — Manner In which the two forms probably origi- 

 nated — Soabiosa and other gyno-dloeoious plants — Difference in 

 the size of the corolla in the forms of polygamous, dioecious, 

 and gyno-dioBcious plants 278-308 



