CORTUSA COTYLEDON. 217 



division. Cuttings strike freely if placed in a coldframe or 

 a cool house under a hand-glass in spring, and when cal- 

 lused, introduced to gentle bottom heat. 



Cortusa. Primulacece. 



Increased by seed sown as soon as ripe, in a coldframe ; 

 . also .by carefully dividing the roots. 



Corydalis. Fumariacetz. 



Increased by seeds, or by dividing the plants directly 

 after flowering. The bulbous-rooted species by offsets. 



Corylus (Hazel, Filbert, Cob-nut). Cupuliferfz. 



Propagated by seeds, suckers, layers or cuttings. 

 Grafting and budding are each practicable, and are 

 adopted when growing tall standards or scarce varieties. 

 The seed of all should be sown as soon as gathered, or 

 stored in sand till the following spring. All superior 

 varieties should be increased by suckers or layers. Stools 

 kept for layering must be allowed to make more growth 

 than those used for suckers. Free growth must be en- 

 couraged for a year or more, and, any suitable time in 

 winter, the shoots should be bent to the ground, pegged 

 firmly, and covered to the depth of 3 inches with earth. 

 They will be well rooted by the following autumn, and 



. .may then be removed and planted out permanently. 



Cosmos. Composites. 



Seeds, usually started under glass. The tuberiferous 

 species like Dahlia, which see. 



Costus. Scitaminece. 



Increased by dividing the roots. 



Cotoneaster. Rosacecz, 



Propagated readily by seed, which should be sown in 

 spring ; by layers or cuttings in autumn, or by grafting on 

 C. vulgaris, the common quince, or the hawthorn. 



Cotton ( Gossypium ) . Malvacece. 



Seeds commonly. When grown as a curiosity under 

 glass, it may be increased by soft cuttings. 



Cotyledon (Navel wort). Crassulacece. 



Increased by seed, offsets, cuttings of the stem, and by 

 leaves. The leaves should be pulled off in autumn, laid 

 on dry sand in pans on a shelf in a propagating or other 



