SELF-FERTILIZATION OF PLANTS. 393 
SCROPHULARIACEX. Limosella aquatica, S. Austr, F. & F., Kerg., S. Af., S. Am., 
N.E. Af., N. Z., N.E. Asia, &c. 
Veronica serpyllifolia, F. & F., N. Z., S. Am., Cal., N.E. Asia. 
LABIATA. Prunella vulgaris, S. Austr., Tas., N. Z., Trop. Asia, S. Am., Jap., Mad., 
N.E. Asia, N. Am. 
VERBENACEÆ. Verbena officinalis, S. Austr., N. Z., Hong., Jap. 
PRIMULACE®. Anagallis arvensis, S. Austr., N. Z., N.E. Af., Jap. 
Samolus Valerandi, N.E. Af., N. Asia, temp. and trop. N. and S. Am., F. & F. 
CHENOPODIACE®. Chenopodium album, S. Am., Hong., Jap., N. Z., N.E. Asia. 
POLYGONACEA. Rumex crispus, S. Austr., F. & F., Hong., N. Z., Mexico. e 
Polygonum aviculare, S. Austr., N. Z., 8. Af., 8. Am., N.E. Af., N.E. Asia, Jap. 
So also P. Persicaria, Trop. Asia, S. Af., S. Am., Fiji, N.E. Asia, N. China, Cal., Soc. I. 
[but P. Bistorta only N. and W. Asia, N. Am.]. 
EvPHoRBIACEAX. Euphorbia Helioscopia, N.Z., Fiji, Hong. 
CERATOPHYLLE®. Ceratophyllum demersum, S. Austr., Trop. Asia, S. Af., S. Am., 
N.E. Af. j 
ALISMACEX. Alisma Plantago, Austr., N.E. Af., N.E. Asia, N.W. India, Am. 
NAIADACEA. Potamogeton natans, Tas., S. AT S. Am, N. Z., N.B. Asia. 
Juncacex. Juncus bufonius, Tas., N.Z., Trop. Asia, S. Af., S. Am., N.E. Af., China, 
India. ` 
CYPERACEÆ. These being frequently proterogynous and wind-fertilized are widely 
dispersed ; thus Luzula campestris is found in S. Aust., Tas., N. Z., S. Af., S. Am. Simi- 
larly Plantago, sp., are found in the southern hemisphere, P. major being in N. Z., Fiji, 
Hong., And. I. 
GRAMINACES. Grasses being mostly wind-fertilized have many species widely diffused ; 
and though some British species, as Keleria cristata, are found in five districts, Poa 
annua, which is self-fertilizing, is found in six, viz., Chili, A. & C., Kerg., N. Z., N.E. 
Af., Jap. Poa pratensis also occurs in F. & F., Kerg., N. Z., Jap. 
The above list, I think, successfully establishes the principle I wish to advance, that, 
without denying the possibility of plants, usually requiring insect-agency to fertilize 
their flowers, becoming occasionally established in distant countries (for we have seen 
how they may become self-fertilizing or else may be visited by native insects), yet the 
proportion of localities where such plants are found is very far less than those of the 
undoubtedly self-fertilizing plants. Hence the inference would seem to be unavoidable, 
that for securing the “end” of plant life (that; seed for propagation) self-fertilizing 
plants are much better favoured than those which are habitually intercrossed. 
For comparison with the preceding I adjoin a list of plants which have conspicuous 
flowers, and are certainly dichogamous (mostly being proterandrous) or heterostyled, 
and which therefore presumably require insect-agency to perpetuate them. It will be 
observed that they are almost all confined to the northern hemisphere. 
.. Delphinium consolida, Mad. Cerastium arvense, Jap., N. Af., W. Asia, N. Am., F. 
Chili. Linum perenne, W. Asia to India. Malva sylvestris, N. Af., Siberia, W. Asia. 
|. Cytisus scoparius, N. Asia, Canaries, and Azores. Anthyllis vulneraria, N. Af., W. Asia. 
p? thes Padus mme ocn N. AL, Sib., W. Asia. meng Salicaria : this ëng = | E 
