3S5-] 



VITALITY OF SEEDS. 



65 



How can I apologise enough for all my presumption and 

 the extreme length of this letter? The great good nature 

 of your letter to me has been partly the cause, so that, as is 

 too often the case in this world, you are punished for your 

 good deeds. With hearty thanks, believe me, 



Yours very truly and gratefully, 



Ch. Darwin. 



C. Darwin to J. D. Hooker. 



Down, 1 8th [July, 1855]. 



... I think I am getting a mild case about Charlock 

 seed;* but just as about salting, ill luck to it, I cannot 

 remember how many years you would allow that Charlock 

 seed might live in the ground. Next time you write, show 

 a bold face, and say in how many years, you think, Charlock 

 seed would probably all be dead. A man told me the other 

 day of, as I thought, a splendid instance, and splendid it 

 was, for according to his evidence the seed came up alive out 

 of the lower part of the London Clay ! ! ! I disgusted him by 

 telling him that Palms ought to have come up. 



You ask how far I go in attributing organisms to a common 

 descent : I answer I know not ; the way in which I intend 

 treating the subject, is to show (as far as I can) the facts and 

 arguments for and against the common descent of the species 

 of the same genus ; and then show how far the same argu- 

 ments tell for or against forms, more and more widely 

 different : and when we come to forms of different orders and 



* In the Gardeners' Chronicle, 

 185 5, p. 758, appeared a notice 

 (half a column in length) by my 

 father on the " Vitality of Seeds." 

 The facts related refer to the " Sand- 

 walk " ; the wood was planted in 

 1846 on a piece of pasture land 

 laid down as grass in 1840. In 

 1855, on the soil being dug in 



VOL. II. 



several places, Charlock {Brassica 

 sinapistrum) sprang up freely. The 

 subject continued to interest him, 

 and I find a note dated July 2nd, 

 1874, in which my father recorded 

 that forty-six plants of Charlock 

 sprang up in that year over a space 

 (14 x 7 feet) which had been dug 

 to a considerable depth. 



F 



