228 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



botanists to V. lorigifolia, being called in nurseries V. I. sub' 

 sessilis. 



It will be inferred from what I have said that internal 

 evidence of the hybrid origin of a plant founded upon its sterility 

 is likely to mislead. Some plants which succeed well in culti- 

 vation, and do not seem to have varied their type, never make a 

 seed in my garden. Malva Munroana, which flowers all through 

 summer, is one of these ; Centaur ea glastifolia (syn. C. Bieber- 

 steini) is another ; though G. macrocephala, which is a native of 

 the same region and flowers at the same time, having a strong 

 general resemblance to it, ripens seed plentifully every year. 



(5) The change which produces double flowers is the last I 

 have to notice ; and whatever doubt there may be whether culti- 

 vation alone, apart from selection and crossing, causes change 

 of colour, I think there can be no doubt that it has a tendency 

 to make flowers come double. I am not going to discuss the 

 causes of doubling, which are no doubt very different in different 

 plants ; I will only say that it does not seem to come from 

 luxuriant growth, or double flowers would come more frequently 

 in my garden than they do. Every hardy plant which produces 

 seed, or of which I can obtain seed, I have raised over and over 

 again from seed, but have rarely raised a double seedling except 

 from a source in which doubles would be expected. Composites, 

 such as Michaelmas Daisies and perennial Sunflowers, often 

 show an inclination to become double, but the seedlings from 

 these semi -double individuals advance no further, whilst double 

 Primroses and double Daffodils often revert to a perfectly single 

 form. Poppies, such as P. umbrosum, and P. alpinum in all its 

 colours, sometimes come double after several generations of all 

 single flowers. Columbines, though I carefully exclude and 

 destroy all doubles, persist in producing double seedlings, even 

 in the hybrids as they approach the type of A. vulgaris. Florists' 

 Delphiniums, Anemone coronaria, and the garden forms of 

 Papaver Bhoeas continue to produce double flowers from the seed 

 of single, even in the cold soil of Edge garden, but these three 

 plants were probably not introduced there from a genuine single 

 stock. 



Summary of deductions under the five divisions of the 

 subject : — 



(1) That individual wild plants when brought into cultivation 



