ii COLOUR-VARIATION 59 



plain that all variegated plants, when grown on their 

 grounds, soon revert to the ordinary type, even when 

 they belong to the most stable varieties, others notice 

 that their garden seems very propitious to the produc- 

 tion of variegations. There is some unknown influence 

 at work in these cases, and experiments might show 

 what it is. 



But it certainly seems that variegated plants cannot 

 be considered as diseased, and M. Lebas x says posi- 

 tively that Euonymus sulfurea, Euonyinus radicans 

 variegata, and Thujopsis dolabrata variegata are cer- 

 tainly stronger and hardier than the common non- 

 variegated varieties; and, on the other hand, MM. 

 Carriere and Andre 2 notice that while Aspidistra 

 clatior variegata has a strong tendency, in most 

 places, to revert to the non-variegated type, there 

 are places where it remains quite constant, and where 

 even non-variegated forms become spontaneously 

 variegated. In some cases variegation comes on 

 slowly, and Vilmorin 3 has studied the process with 

 care, but in others it comes on all of a sudden. 

 Carriere 4 has noticed a case of this sort in a garden 

 where thousands of celery plants were growing, and 



1 De qtielqttes Fusains du Japan a Feuilles panachees. Rev. 

 Horticole, 1872, p. 139. 



-' Revue Horticole, 1888, p. 124. 



;i Stir les Panachures des Fleiirs. Ibid. 1852, p. 128. 



4 Panachurc dn Ccleri. Rev. Horticole, 1882, p. 541. 



