[4]

(2

(Although worms they are indifferent to undulations in the air audible by us, they are extremely sensitive to vibrations in the soil. When the pots, with the two worms emerged from the burrows which had remained quite indifferent to the sound of the pianoforte, were placed on this instrument, & the note C in the base clef was struck, the two both instantly retreated into their burrows. After a time they emerged, & when G in the treble clef was struck they again retreated. Under similar circumstances on another night as when one worm dashed into its burrow as soon a on a very high note being on a strike, & the other when C in the treble clef was struck. On these occasions the pots the pots stood in saucers & the worms did not touch the sides of the pots which stood on saucers; so that the vibrations had to pass from the sounding board of the

[4v]

385

Petunia

We here see that judging by weight, instead of as before by height, that the Westerham-crossed and the intercrossed have an immense advantage over the self-fertilised. The Westerham-crossed are inferior to the intercrossed by a mere trifle; but it is almost certain that if they had been allowed to go on growing for another month, the former would have completely beaten the latter.

As I had an abundance of seeds of the same three lots, from which the foregoing plants had been raised, these were sown in three long parallel and adjoining rows in the open ground, so as to try whether under these circumstances the results would be nearly the same as before. Lately in the autumn (Nov. 13) the ten tallest plants were carefully selected out of each row, & their heights measured, with the following result.