GENERAL REVIEW. 



pollen being impotent, so far as self-impregnation is concerned, 

 although potent when applied to the stigma of other species. 

 M. Delaire, of the Orleans Botanic Garden, long occupied 

 himself in hybridising Passion-flowers ; and he was one of the 

 first to record the fact that some species are sterile when their 

 own pollen is used, but fertile when .that from another species 

 or variety is applied. P. amabilis (see List) is a hybrid ob- 

 tained by M. Schachter, of Loos-les, Lille, and is the result of 

 fertilising P. raccmosa with pollen of P. alata. M. Belat, of 

 Moulins, also obtained hybrids in 1847 by fertilising P. alata 

 with pollen from P. c&rulea. P. Lemicheziana was obtained be- 

 fore 1845 by M. Lemichez, and is the result of seeds obtained 

 from P. alata fertilised with pollen from P. Raddiana (P. 

 kermesina, Hort.) Pollen of the last-named plant, according 

 to M. Lemichez, will always fertilise the ovules of P. alata, 

 and produce a fair percentage of perfect seeds ; but the cross 

 cannot be reversed. This is one of the many exceptions to 

 the rule of elective or constitutional affinity as laid down by 

 Wichura (see p. 154). Many of the Passifloras, especially those 

 bearing edible fruits, are widely cultivated in the tropics, espe- 

 cially in South America and the West Indies so that, what 

 with seminal and cultural variation, together with natural and 

 artificial hybridisation or intercrossing, there are many points 

 in their history rather perplexing to the botanist and horticul- 

 turist ; and previous to the monograph published by Dr M. S. 

 Masters, the confusion of names was as bad as can well be 

 imagined. P. ccerulea is perfectly hardy as far north as 

 York, and fruits freely in London gardens, its fruit being 

 of a soft orange - yellow colour, egg-shaped, and generally 

 containing perfect seeds, artificial fertilisation not being ne- 

 cessary. 



The following varieties known or supposed to be hybrids 

 are given in Dr Masters's " Classified List of Passiflorese " (see 

 'Jour. Royal Hort. Soc.,' iv. 125) : 



P. albo-nigra, Regel, 'Gart. Fl.,' 1852, t. 8. Said to be a 

 cross between P. alata and P. Raddiana. 



P. amabilis, Hort. ? This is said to be a hybrid between 

 P. racemosa as the seed-parent and P. alata. 



P. alato-ccerulea, W. Mast, in ' Bot. Reg.,' p. 848. A hybrid 

 between P. alata and P. ccerulea, raised at Canterbury. 



P. " Bijou." Said to be a hybrid between P. racemosa and 

 P. Raddiana. 



P. Belottii, Hort. Regel., 'Gart. Fl.,' 1852, p. 44; 'Card. 

 Mag. Bot.,' vol. i. Said to be a cross between P. ccemleo- 

 racemosa and P. quadrangidaris. 



