220 GENERAL REVIEW. 



potted off too soon. Seed collected abroad should be left in 

 the pulp, which, being its natural protector, prevents the air 

 acting on it, and drying it up ; packed in a small tin box, it 

 may be sent any distance without losing its vitality. The best 

 flowering varieties are Cereus speciosissimus, and its varieties, as 

 C. Ackermanni, C. Jenkinsoni, C. splendens, and others ; these 

 are the forms most commonly grown in cottage - windows. 

 The genera Phyllocactus and Cereus contain many fine- 

 flowering varieties. 



" Hybridisation may be performed with ease, as the stamens 

 and pistils are so very distinct, and the pollen produced in 

 abundance. It may be preserved for some time if kept in a 

 bottle hermetically sealed. I have not met with any successful 

 attempt to cross Mammillaria with Echinocactus, or Opuntia 

 with Cereus, though I know of no cause why they may not be, 

 as the differences in the flowers are not differences of structure, 

 but merely degrees of development, such as a greater or lesser 

 number of stamens or petal* ; or in the absence in some, and 

 lengths in others, of the tube of the corolla, excepting that it 

 may be that the pollen-tubes might be too strong for the dis- 

 tance they have to grow from the apex of the stigma, or vice 

 versa." 



It may be well to point out here the fact that most of the 

 large-flowered scandent species of Cereus, as 'C. grandiflorus, 

 C. (restrains) hamatus, and C. Macdonaldice, together with some 

 of the columnar species, are night-flowering plants ; and it will 

 be necessary to watch the flowers closely to catch the stigma 

 at its receptive period, as well as to prevent self-impregnation. 

 Possibly it may be necessary to cut open the flowers before 

 they expand, in order to make sure that the receptive surface 

 is in a pure or virgin state. Cereus speciosissimus is one of the 

 most brilliant-flowered species in the genus, and has already 

 been used in hybridising with C. oxypetalus, Phyllocactus Acker- 

 manni, and others. Many seedling or hybrid forms of Phyllo- 

 cactus and Cereus speciosissimus have been raised in gardens ; 

 and among these C. splendens and P. Gordoniana are grown at 

 Kew, and arc remarkably ornamental in June when in bloom. 

 The first-named has widely-expanded crimson-scarlet flowers, 

 while the latter plant bears flowers of a soft rose colour. About 

 1870, Col. Charleton, of Farm Hill, Braddan, Isle of Man, 

 bloomed a series of very beautiful hybrids, obtained by him as 

 the result of crossing Cereus speciosissimus with Phyllocactus 

 crenatus a white-flowered species. Some of these seedlings 

 were very handsome, bearing large flowers, the colours of which 

 varied from white through all shades of peach, rose, and rosy- 



