ii6 THE COLOURS OF FLOWERS. 



flowers here described as primitive is usually identi- 

 cal in composition with the ordinary yellow chloro- 

 phyll of leaves, while the orange, pink, red, and blue 

 pigments are of more elaborate kinds. 



If the botanical reader will provisionally accept the 

 principles laid down in this little book, and will then 

 test their validity by applying them to the flowers 

 which he meets in his daily walks, he will find that 

 many other confirmatory examples occur to him at 

 every step, most of which are too numerous to insert 

 here. He will also often find that close inspection 

 reveals some unexpected answer to a superficial 

 difficulty, some solution for the problem of an ap- 

 parent exception, which can only be obtained by 

 personal examination of the specimen with that 

 particular object held definitely in view. For ex- 

 ample, the case of the dead-nettle (Lamium album} 

 was cited above as one of a labiate grown white by 

 reversion (Fig. 45). This may have seemed at the 

 time a purely gratuitous and arbitrary supposition. 

 Why should not the white form be primitive, and the 

 purple or pink ones be derived from it ? But if 

 the flower of a dead-nettle be carefully examined, 

 it will be found in most cases to be not purely white, 

 but to have some dusky fines and markings on its 

 lower lip, of a pale brown or dim grey-black, which 

 exactly answer to those on the lip of L. maculatum, 

 and in a less degree of L, ptirpureum. Now, such 

 markings do not occur among original white flowers 

 like the crucifers and Caryophyllacece ; but they are 

 common on the lower lip of purple labiates. More- 

 over, we know that Lamium maculatum is very closely 

 allied to L. album, and that it is purple-red instead 



