Vlll PKEFACE TO THE FOUKTH EDITION. 



mixture of the blood of the Asiatic species and 

 varieties ; to this they owe their vivid color, but 

 this same cause unfits them for open air culture in 

 our climate, as they are of too delicate a constitution 

 to withstand the severity of our winters, or flower 

 too early for our uncertain springs. In greenhouse 

 varieties, some fine hybrids have been raised in the 

 Sikkim class. These are well worthy of cultiva- 

 tion where there is sufficient room under glass, and 

 require only the general culture given camellias, 

 thriving in the same temperature. In this country, 

 while many seedlings have been produced, we have 

 seen none superior in form or color to the old varie- 

 ties. This superiority we can hardly hope for, but 

 we majr attain by judicious hybridization increased 

 hardiness, larger foliage, and greater substance of 

 flower. 



It is as yet too early to decide whether in these 

 respects American seedlings are acquisitions. 



In Azaleas there has been some progress. Many 

 seedhngs have been raised from Azalea mollis, a 

 well known Japanese species, which for size and 

 color of flower and floriferous quality are decided 

 acquisitions. These seedlings will probably prove 

 hardy, though there is danger of the flower-buds 

 being killed in severe winters. As far as tried, the 

 plants seem to have a good constitution, although it 

 is yet too soon to speak confidently as to their hardi- 



