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THE VITALITY AND DISTRIBUTION OF SEEDS. 
B y J. C. Siienstone, F.L.S. 
The “ great Essex naturalist,” John Bay, has placed on record 
that after the Great Fire of London Sisymbrium Irio came up in 
great abundance in 1667-68 amongst the ruins of the City. in 
Bay’s time most doctors and apothecaries were botanists, and were 
quite familiar with our wild and cultivated plants; and there can be 
no doubt that this sudden profusion of a rare plant presented to them 
a most interesting problem. The only attempt at a solution of the 
problem, in Bay’s time, appears to have been that of Robert Morison, 
Professor of Botany at Oxford, who included a very long dialogue 
upon the subject in his Brceludia Botctnica (1669). He suggests 
that the plants were produced by spontaneous generation from the 
fixed and volatile salts, sulphur, etc.—a solution which certainly 
would not appeal to any Oxford professor of the present day (see 
Baxter, Brit. Flowering Plants, ii. pi. 146; 1885). 
The phenomenal appearance of a luxurious crop of plants, often 
new to the district, which almost invariably follows the making of 
railway-cuttings, the excavating of wells, the dredging of canals, or 
the levelling of building-sites, was as little understood by modern 
botanists as by those of the time of the Great Fire, until recent 
researches threw some light upon it. 
The solution of the problem clearly depends upon two lines of 
enquiry :—(1) The length of time that seeds may retain their vitality 
when embedded in the earth at different depths under natural con¬ 
ditions; and (2) a more thorough investigation as to the distribution 
of seeds of wild plants. 
The preservation of the latter obviously depends largely upon the 
successful deposition of their seeds in such a manner as to safeguard 
the rearing of future generations of the species. Had not the two 
hundred thousand known species of phanerogams succeeded in this 
during the many thousands of years of their existence, the world bora 
would have disappeared long ago. The problem must, therefore, be 
regarded as one of exceptional interest. 
Vitality. 
Practical agriculturists and horticulturists have learnt bv ex- 
O i ( 
perience that most seeds, when preserved for future use, quickly 
deteriorate under ordinary conditions. But until recently very little 
was known of the vitality of wild seeds in natural conditions. Our 
knowledge of seed-vitality has been extended by the researches of 
Becquerel, Ewart, and Duvel. 
Becquerel (Ann. Sci. Nat. Bot. ser. 9, v. pp. 193-810; 1907) 
tested the germination of all the oldest seeds of known age (from 
25 to 135 years) preserved in the Natural History Museum of Paris. 
The seeds of 500 species, included in 30 families, were tested, but 
only 50 of these produced seedlings, and all of these belonged to four 
families, mostly Leyuminosce, with a few JSfelumbiaccm, Jlfalvctcea, 
Journal of Botany.—Vol. 61. [December, 1923.] z 
