8 THE GARDENER. [Jan. 



European and American species and hybrids. At the same time con- 

 siderable progress has been made, and already a few fine hardy hybrids 

 have been introduced; while a new race of valuable greenhouse varie- 

 ties — the result of crossing among themselves — has been created, which 

 are already high in popular favour. 



In crossing Rhododendrons with a view to obtain hardy and late- 

 flowering seedlings, we invariably choose the hardiest variety for the 

 female parent, being satisfied from experience that the offspring in- 

 herit much more of the nature of the female than of the male in this 

 respect ; and when one of the sorts is tender, there is no species that 

 we know of better adapted to form the basis of a hardy race than R. 

 Catawbiense, which combines elegant foliage and showy flowers with 

 an ability to bear any amount of frost that it can be subjected to in 

 this country, along with a tendency to flower freely in a young state. 

 It has been largely used by the most successful hybridisers, and its 

 presence can easily be detected in some of our most useful and showy 

 hardy hybrids. 



R. maximum is also an excellent species for hybridising with 

 the tender sorts, being hardy and late-flowering, and having fine com- 

 pact trusses, the florets clear in colour and of a thick wavy texture, 

 enabling them to resist hot sunny weather better than most sorts ; but 

 it has the drawback of being a shy bloomer, and is used with greatest 

 advantage after being first crossed with some of the free-blooming 

 sorts. Some of the finest varieties have been obtained from its hybrids. 



When early-forcing sorts are the objects in view, by far the best is 

 R. Caucasicum, itself so early as frequently to expand its blush- 

 coloured flowers in mid-winter in the open air. It is dwarf in habit, 

 and a most prolific bloomer ; and it has produced many most admir- 

 able varieties for such a purpose, including Noblicanum and jSTobli- 

 canum album, first crosses by Arboreum and Cinnamomeum, both of 

 which are invaluable for conservatory decoration from the middle of 

 December till the end of February — a season when effective flowers 

 are neither plenty nor varied. 



Hugh Eraser. 

 {To he continued.) 

 Leith Walk Nurseries, 

 Edinburgh. 



