1843-1862] VITALITY OF SEEDS 245 



The vitality of seeds was a subject in which Darwin continued to take 

 an interest. In July, 1855 (Life and Letters, II., p. 65), he wrote to 

 Hooker: "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." 



In the Gardeners' Chronicle, 1855, p. 758, appeared a notice (half a 

 column in length) by Darwin on the " Vitality of Seeds." The facts 

 related refer to the " Sand-walk" at Down ; 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 several places, Charlock (Brassica sinapistruni) sprang 

 up freely. The subject continued to interest him, and we find a note 

 dated July 2nd, 1874, in which Darwin 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. In the course of the article in 

 the Gardeners' Chronicle, Darwin remarks : " The power in seeds of 

 retaining their vitality when buried in damp soil may well be an element 

 in preserving the species, and therefore seeds may be specially endowed 

 with this capacity ; whereas the power of retaining vitality in a dry 

 artificial condition must be an indirect, and in one sense accidental, 

 quality in seeds of little or no use to the species." 



The point of view expressed in the letter to Lyell above given is 

 of interest in connection with the research of Horace Brown and F. 

 Escombe J on the remarkable power possessed by dry seeds of resistance 

 to the temperature of liquid air. The point of the experiment is that life 

 continues at a temperature "below that at which ordinary chemical 

 reactions take place." A still more striking demonstration of the fact 

 has been made by Thiselton-Dyer and Dewar, 2 who employed liquid 

 hydrogen as a refrigerant. The connection between these facts and 

 the dormancy of buried seeds is only indirect ; but inasmuch as the 

 experiment proves the possibility of life surviving a period in which no 

 ordinary chemical change occurs, it is clear that they help one to believe 

 in greatly prolonged dormancy in conditions which tend to check 

 metabolism. For a discussion of the bearing of their results on the 

 life-problem, and for the literature of the subject, reference should be 

 made to the paper by Brown and Escombe. See also C. de Candolle 

 "On Latent Life in Seeds," Brit. Assoc. Report, 1896, p. 1023; and 

 F. Escombe, Science Progress, Vol. I., N.S., p. 585, 1897. 



To J. S. Henslow. Letter 



Down, Saturday [Nov. 5th, 1843]. 



I sent that weariful Atriplex to Babington, as I said I 

 would, and he tells me that he has reared a facsimile by sowing 



1 Proc. Roy. Soc., Vol. LXIL, p. 160. 



Read before the British Association (Dover), 1899, and published 

 in the Comptes rendus, 1899, and in the Proc. R. Soc., LXV., p. 361, 1899. 



