Adams — On the Germination of the Seeds of some Dicotyledons. 469 



and were found to have become rotten. As the seeds were those of the 

 previous season, it is difBcult to understand their failure to germinate- 

 Possibly the fact that they were not sown till January may have something 

 to do witli it. 



Another object of the investigation was to obtain specimens of the 

 seedlings. The chief source of information on this subject is Lubbock's 

 large work " A Contribution to our Knowledge of Seedlings," two vols., 1892. 

 More recently, H. Coupin, in "Les Graines Expliquees," 1909, gives descrip- 

 tions of the germination of a number of economic plants. In the case, 

 however, of a large number of our native species nothing is known of 

 their germination. The present paper contains descriptions of 158 species 

 that are not enumerated in Lubbock's treatise. Altogether observations were 

 made on 278 species belonging to 190 genera, and 58 families of Dicotyledons- 

 With a few exceptions, all the species enumerated are natives of the British 

 Isles. The exotic species are :— Plum, Peach, Almond, Virginian Prune, 

 Pear, Grape-Vine, Orange, Lemon, and Fig. 



The following species may germinate in the same year in which the seeds 

 are ripened, and therefore normally pass the winter in the seedling stage : — 

 Arenaria verna, Lychnis dioica, L. Githago, Bellis perennis, Leontodon nadicauUs, 

 Taraxacum officinale, Tiissilago Farfara, Salvia Verhenaca, Lotus corniculaius 

 Vicia Cracca, Beseda Luleola, CaucaUs nodosa. There seems to be little doubt 

 that this list could be greatly extended by future observation. 



Subterranean cotyledons occur in the following : — Lathyrus, Vicia, 

 Rhcmimis Frangula, Almond, Peach, Virginian Prune, Rubia peregriiia, and 

 Lemon. It is noteworthy that, in some species of the genera Prunus and 

 Ehamnus, the cotyledons remain below, while in other^ species they come 

 above ground. 



Seedlings of Yellow Rattle were allowed to grow in order to determine 

 whether they could develop witliout obtaining nourishment from the roots of 

 other plants. In all eases, however, they failed to grow to maturity. 

 Previous attempts to germinate the seeds of this species resulted in failure. 

 It is essential for their germination that the seeds be buried in soil as soon as 

 they are scattered from the parent plant. 



It is well known that Leguminous plants produce a certain number of 

 " hard" seeds, that is, seeds which remain impermeable to water for a long 

 time, and while in this condition they do not germinate. The largest 

 percentage of these " hard " seeds that I have observed in any one species was 

 in the case of Vicia sepiuni. Out of one lot of tweuty seeds planted in 

 October none had germinated after nine months. Another lot of seeds was 

 sown in July ; after six months one had germinated, and five months later 



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