ON PROPAGATION BY SEED. 247 



1838, M. Regel, of Berlin, gathered seeds of Draba prae'cox, and sowed them 

 in pots which were kept in a cold pit. Only two plants came up that year, 

 of very stunted growth, and they never attained sufficient strength to 

 flower; while next spring the remaining seeds came up very thick and 

 strong, and flowered in the space of four weeks. On the other hand, the 

 seeds of the greater portion of biennial plants, if sown immediately after 

 ripening, come up freely, become strong plants before winter, and flower 

 the following year. This is also the case with a great number of annual 

 plants, especially those of California, which in their native country spring 

 up before winter, and are preserved through that season by a covering of 

 snow. The seeds of crataegus, mespilus, ilex, prunus, cerasus, and some 

 others, if sown immediately after being gathered, will in part come up the 

 following spring, but chiefly in the second spring, though some will not 

 germinate till the third or fourth season. If these seeds, instead of being 

 sown immediately after gathering, are dried and sown the same autumn, 

 none will come up till the spring of the second year. This holds good also 

 with the seeds of a number of trees and shrubs, among which may be 

 mentioned daphne, ribes, rubus, rosa, potentilla, berberis, pseonia, &c. 

 De Candolle mentions a sowing of tobacco which continued to send up 

 plants in sufficient numbers to form a crop every year for ten years. It is 

 a common occurrence to find plants, especially annuals, springing up in 

 ground newly brought into cultivation, after it had been used many years 

 for other purposes. Thus, a field of grass, that was ploughed up near 

 Dunkeld, in Scotland, after a period of fourteen years in turf, yielded a con- 

 siderable crop of black oats without sowing. Mustard-seed has sprung up 

 in the fern lands, which must have lain there upwards of a century ; and 

 white clover, it is well known to every agriculturist, springs up, on the. 

 application of lime in soils, where it had not been before seen in the memory 

 oilman. In pulling down old buildings, seeds capable of germinating have 

 been found in the clay used as mortar. The seed of Veronica hederaefolia, 

 -L., after heavy rains, has been known to spring up on the surface of fields, 

 where previously no trace of that plant was to be found. At Gottingen, M. 

 Regel found Alsine Segetalis, L. come up in great profusion, which had not 

 been found there for more than twenty years. He also found Rumex mari- 

 timus, Zr., and Cyperus fuscus, Z,., thickly overspreading the bottom of a 

 pond that had been dried the year before no trace of these plants being 

 to be found in the neighbourhood, and the pond having, for many years, 

 been kept full of water (Gard. Mag. for 1841, p. 480). 



568. The season for sowing seeds is, in nature, when they are ripe, but 

 in artificial culture it varies according to the object in view. The spring, 

 however, is the most favourable period for germination, because at this 

 season the vegetable kingdom awakens from the sleep of nature. Seeds 

 removed from foreign countries, and also the seeds of any rare indigenous 

 plant, should be sown as soon as they are removed or gathered, in a soil 

 and situation favourable for germination and growth. For a succession of 

 crops of annual culinary plants, or annual flowers, the gardener sows at 

 different periods ; and in the case of biennial plants, he sows in the autumn. 

 The following are the results of experiments made by Mr. G. Gordon, of 

 the Hort. Soc. Garden, upon raising plants from seed : " All seeds from 

 North America and California should be sown in the autumn as soon as 

 ripe ; to defer the sowing them till the spring may in all cases be disadvon- 



