VI.] YELLOW BUGLE. 129 



the other. Moreover, though I was fortunate in 

 lighting on so good an illustration as that shown ih 

 the figure just when I had the opportunity of photo- 

 graphing it, still every one must have observed that 

 the two species are very commonly found growing 

 together. Assuming that the ancestor of the Dead- 

 nettle had leaves possessing a faint resemblance to 

 those of the true Nettle, those in which the likeness 

 was greatest would have the best chance of survival, 

 and consequently of ripening seeds. There would be 

 a tendency, therefore, according to the well-known 

 principles of Darwin, to a closer and closer resem- 

 blance. I am disposed to suggest whether these re- 

 semblances may not serve as a protection, not only 

 from browsing quadrupeds, but also from leaf-eating 

 insects. On this part of the subject we have as yet, 

 however, I think, no sufficient observations on record. 



Ajuga champapitys, the yellow Bugle, has leaves 

 crowded and divided into three linear lobes, the lateral 

 ones sometimes again divided. They differ, therefore, 

 greatly from those of its allies, and this puzzled me 

 much until one day I found it growing abundantly on 

 the Riviera among Euphorbia cyparissias, and I was 

 much struck by the curious likeness. The Euphorbia 

 has the usual acrid juice of the genus, and it struck 

 me that the yellow Ajuga was perhaps protected by 

 its resemblance. 



Leaves which float on the surface of still water 

 tend to be orbicular. The water-lilies are a well- 

 known illustration. I may also mention Limnan- 

 thenum nymphceoides, which, indeed, is often taken 

 for a water-lily, though it really belongs to the family 



K 



