Vegetable and Animal 



Sometimes, as we have seen, they are so like the 

 stones or sand of the desert that they cannot be easily 

 picked out ; sometimes also plants which are quite good 

 to eat so resemble others which are not, that they are 

 left alone by grazing animals. 



The white dead nettle (Lamium album) and the sting- 

 ing nettle is the example which is most often selected, 

 though recently some doubt has been expressed about 

 the actuality of the protection. It is a fact, however, 

 that a patch of stinging nettles will hold their own for 

 some fifty years at least in a park regularly grazed 

 by cattle. (Their favourite position is in the richly 

 manured soil under the shade of the widely spread 

 foliage of an oak or other large tree.) 



So that cattle do not habitually eat nettles. But it is 

 not certain that they would in any case devour the dead 

 nettle, for the Labiate order is not a favourite on account 

 of its strong scent. 



Both stinging and dead nettles are most often found 

 by hedges and roadsides. There they have to maintain 

 themselves against boys and girls, who are the most 

 destructive of all animals. A rhinoceros will, in a fit 

 of fury and bad temper, trample down and break into 

 tiny pieces large bushes of acacia. Man, in this unde- 

 veloped stage, is also capable of the wanton destruction 

 of vegetables, but apparently no other animal. 



A very interesting puzzle in mimicry is the fact that 

 in Australia some of the parasitic Loranthus, allied to 

 our mistletoe, closely resemble in leaf the acacias upon 

 which they grow. This was discovered by Drummond 

 and has been confirmed by Mr. Moore. The ordinary 

 leaves of most acacias are utterly unlike those of the 

 ordinary Loranthus. Mr. Moore states that camels 

 browse upon the Loranthus, but do not touch the acacia 

 leaves.*'^ 



196 



