15? ON THE NATURALIZATION OF FLANTS. 



getable fubllances are, by which they impart to the plant heat 

 and moifture (the two principal agents which caufe vegetation) 

 thereby putting the vegetating powers in action, and filling 

 the plant with fap, at an improper feafon. In our culture of 

 annuals our only care is directed to placing them in proper 

 foils and expofures. For, that no region of the earth fliould 

 remain uninhabited, with a liberal hand have the annual plants 

 been diftributed ; from thefe do men and animals derive their 

 principal fupport, and of all the vegetable kingdom, they are 

 bell adapted for naturalization. By bringing their feed to per- 

 fection in a fingle feafon, they are capable of cultivation in a 

 greater variety of climates than any other vegetables, And 

 the feed, being equally undeftroyed by natural heat and cold, 

 lies dormant, till genial weather calls forth its latent powers, 

 and urges it to vegetation, whether among the frozen fnows 

 of Siberia, or the burning fands of Africa. The refeda odorata 

 (mignionette), a native of Egypt, and helianthus annuus (fun- 

 flower), of Mexico and Peru, ripen their feed, and are thereby 

 perpetuated in our northern latitudes. St. Pierre * fays, the 

 peafants of Finland cultivate tobacco (nicotiana tahacum) , with 

 fuccefs, beyond the fixty-firft degree of latitude; and that 

 barley fucceeds in the very bofom of the north. Amidft the 

 rocks of Finland he faw crops of this grain as beautiful as ever 

 the plains of Paleftine produced f. 

 Criterions by When we endeavour to naturalize plants, that we may dif- 



exo't cs may be ^i n g u i m thofe which offer the fairefi profpect of fuccefs, a 

 diftinguifhed. comparifon of the exotics with the natives of the foil will be 

 our furefr. guide. Thus we find, that throughout the frofty 

 regions of the north, the trees, Ihrubs, bulbous and perrennials, 

 complete their (hoots, and, before the cold of the winter com- 

 mences, enclofe in hybernacule or fcaly buds, the embryo for 

 the coming year. And there is every reafon to believe that all 

 exotics will ceafe growing, and form thefe buds or hybernacule 

 in the open air during the courfe of our fummer, will not fufFer 

 from the feverity of our winter. In the hot-houfe many plants 

 complete their (hoots that would not probably do fo in the 

 open air, the heat not being fufficient to caufe them to grow 

 with the vigour neceflary for their completion before winter. 



* See St. Pierre's Studies of Nature, tranflated by Hunter, Dub- 

 lin edition, Vol. I. page 604. 



f See the fame Work, page 667. 



Neverthelefs 



