174 THE STRUCTURE OF FLOWERS. 



CHAPTER XIX. 



COLOURS OF FLOWERS. 



The Laws of Colour. — M. de Candolle proposed to divide 

 the colours of flowers into two series, the Xanthic and Cyanic, 

 the former containing yellow-green, yellow, yellow- orange, 

 orange and orange-red ; the latter, blue-green, blue, blue- 

 violet, violet, and violet-red ; red being intermediate between 

 the two series. It was thought that flowers were rigidly 

 bound by these series, and never transgressed them, but that 

 the tints of a species might vary through each. Thus the 

 editor of the Gardener s Chronicle, replying to a correspondent 

 on Feb. 2, 1842 (p. 97), remarks that "a blue Dahlia was 

 not to be expected. On the other hand, the Hyacinth, being 

 of the cyanic series, a yellow Hyacinth will not occur." 



Yellow Hyacinths are, however, common enough now. 

 Even in 1856, Dr. Lindley found it necessary to conclude a 

 leading article on the subject with the words : "At all events 

 the cyanic and xanthic speculations of philosophers must now 

 be laid up in the limbo of pleasant dreams." 



The many exceptions to this supposed rule met with 

 between 1845 and ]856 elicited the above remark, and 

 notably a species of Delphinium, viz. D. Cardinale, containing 

 " golden yellow in the petals, which are as scarlet as a 

 soldier's jacket everywhere else, one of the last of Messrs. 



