470 On the Cultivation and Management of the Cactus tribe. 



effected abortive fecundation with these, by dusting the Cereuses 

 and Epiphylla with the pollen of Echinocactus Ottonis ; but though 

 the seed vessels would ripen seeds to all appearance quite perfect, 

 the seed wanted the embryo. This is a common occurrence in 

 extensive families. The Cerei, of which the Epiphylla are a subsec- 

 tion, are the great laboratory for improving the fine flowering Cacti. 

 Much has already been effected by crossing these plants, and much 

 more remains yet to be accomplished among them in this way. To 

 say nothing of mixing new species with the older ones for the sake 

 of brilliant colours, we might easily get a new race of free flower- 

 ing ones in the way of Cereus grandiflorus, by a judicious mix- 

 ture of such species as Cereus nycticallis, C. triangularis and its 

 near relative C. Napoleonis, with that splendid new Cereus which 

 is sold in the London nurseries under the erroneous name of se- 

 taceus, but which has no resemblance to the true setaceus of Prince 

 Salm Dyck, farther than being, like it, three angled. This noble 

 Cereus is not described by Dr. Pfeiffer, and I think it has been 

 only introduced to some collection in this country and not yet de- 

 scribed ; however, it is the finest of the genus, and by it a new race 

 of splendid Cacti may be obtained ; its flowers are as large as those 

 of C. grandiflorus, and of a brilliant yellow colour, of the African 

 marygold tint. This Cereus, and C. nycticallis which is the freest 

 and perhaps the largest flowering sort we have, ought to be in every 

 collection. This yellow flowering cereus could effect wonders with 

 the C. speciosissimus and its seedlings, and produce a new race 

 having all the brilliancy and tints of the Azalea. 



