CHAPTER IV.
HETEROSTYLED TRIMORPHIC PLANTS.

Lythrum salicaria.--Description of the three forms.--Their power and complex
manner of fertilising one another.--Eighteen different unions possible.--Mid-
styled form eminently feminine in nature.--Lythrum Graefferi likewise
trimorphic.--L. hymifolia dimorphic.--L. hyssopifolia homostyled.--Nesaea
verticillata trimorphic.--Lagerstroemia, nature doubtful.--Oxalis, trimorphic
species of.--O. Valdiviana.--O. Regnelli, the illegitimate unions quite barren.-
-O. speciosa.--O. sensitiva.--Homostyled species of Oxalis.--Pontederia, the one
monocotyledonous genus known to include heterostyled species.


CHAPTER V.
ILLEGITIMATE OFFSPRING OF HETEROSTYLED PLANTS.

Illegitimate offspring from all three forms of Lythrum salicaria.--Their dwarfed
stature and sterility, some utterly barren, some fertile.--Oxalis, transmission
of form to the legitimate and illegitimate seedlings.--Primula Sinensis,
illegitimate offspring in some degree dwarfed and infertile.--Equal-styled
varieties of P. Sinensis, auricula, farinosa, and elatior.--P. vulgaris, red-
flowered variety, illegitimate seedlings sterile.--P. veris, illegitimate plants
raised during several successive generations, their dwarfed stature and
sterility.--Equal-styled varieties of P. veris.--Transmission of form by
Pulmonaria and Polygonum.--Concluding remarks.--Close parallelism between
illegitimate fertilisation and hybridism.


CHAPTER VI.