individual than it is for impregnating the ovules of its own flower. 
The advantage gained by fertilizing one plant with the pollen from a 
distinct individual of the same species is admirably demonstrated by 
some experiments recorded by Mr. Darwin,* in which he shows that 
seeds from self-fertilized and crossed (one individual by pollen of 
another plant of the same species) unions, when sowed close together 
and equally favoured, prove, by their growth, in their struggle for mas- 
tery, that the latter are stronger and more productive than the for- 
mer. We have seen that the pistillate-flowered Calamintha produced a 
great abundance of seed, and we may now, I think, conclude that this 
species is all the more flourishing and vigorous because it produces two 
forms, thus necessitating the importation of pollen from a distinct 
individual. 
ExpLaNaTion oF Prate LXII.—Fig. A 1, pistillate flower. <A 2, 
corolla of the same cut open.. A 3, calyx cut open. A 4, an achene. 
A 5, the same, of the natural size ; all the Figs., except A 5, magnified. 
Fig. B 1, flower from a distinct, hermaphrodite plant, magnified. B 2, 
corolla of the same cut open. Fig. C 1, hermaphrodite flower, magni- 
fied. C 2, corolla of the same cut open, magnified. C 3, an achene, 
magnified. C 4, the same, of the natural size. Fig. D 1, pistillate 
flower, magnified. D 2, corolla of the same cut open, magnified. D 3, 
fruiting calyx, magnified. D 4, achene, magnified. D 5, the same, of 
the natural size. 
* ¢ Animals and Plants under Domestication,’ ii. 127. 
