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.” 
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