88 On the different Species of Dahlia. 



following reasons ; 1st, herbaceous plants so tall and tender 

 are seldom met with in high mountains, the dominions of 

 winds, snows, and storms ; 2<%, these plants, when exposed 

 to a temperature of 7 or 8 degrees below zero, turn yellow 

 and sick ; 3dhj, they are late in beginning to vegetate, and 

 require a Jong protracted autumn to expand their flowers : 

 Uhly, their roots had been already killed at Paris, by a frost 

 of five degrees in one night. Notwithstanding this unfavour- 

 able statement, Monsieur Thouin does not despair of being 

 able in time to change their habits, and acclimate them in 

 France : to this end, he proposes forwarding them in spring 

 with a little artificial heat, and wisely remarks that our days 

 in summer being longer than in Mexico, a sufficient maximum 

 of heat to bring their flowers and seeds to perfection may 

 thus be obtained ; that thus Barley, which in the north of 

 France, requires six months to ripen in, is often perfectly 

 matured in Russia, in forty days. He then brings instances of 

 two plants from the same country, the Marvel of Peru, and 

 Long-flowered Marvel of Peru, which, though very tender when 

 first introduced, are now become more hardy, the former, es- 

 pecially, often springing up in their parterres, from self-sown 

 seeds. Lastly he informs us, that all the Dahlias may be in- 

 creased by seeds, dividing their roots, or even by cuttings of 

 their stems, though that part is annual ; but seedling plants, 

 he remarks, do not flower the first year, and the memoir con- 

 cludes with some general remarks on the beauty, and orna- 

 ment, which they will add to our borders or conservatories, 

 in autumn. 



The fifth author upon this genus is Professor Willdenow, 

 who in his Species Plant arum most unwarrantably changes 



