328 



BRITISH FLOWERING PLANTS 



The Dead-nettle is so called because in the form 

 of the leaf and in general habit the plant so closely 

 resembles young plants of the Stinging-nettle, although 

 the two species belong to very different families. How 

 close the similarity is may be seen by the following 

 illustration taken from a photograph. The plants on 

 the right are true Stinging-nettles ; those on the left are 

 the white Dead-nettle, one of which is in flower. So 

 close was the resemblance that after getting the photo- 

 graph I went back to the spot on which they were 

 growing to assure myself that there was no mistake. It 



cannot be doubted that 

 the true Nettle is pro- 

 tected by its power of 

 stinging; and that 

 being so, it is scarcely 

 less clear that the Dead- 

 nettle must be protected 

 by its likeness to the 

 other. Moreover, 



though I was fortunate 

 in lighting on so good 

 an illustration as that 

 shown in the figure, 

 just when I had an opportunity of photographing 

 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 resemblance. I am disposed to suggest 

 whether these resemblances may not serve as a protec- 

 tion, 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 sufiicient observations on 

 record. 



Fia. 214. — Group of Dead-nettles and 

 Stinging-nettles. 



