PLANTS THAT MIMIC 33 
A very different reason for mimicry is that 
shown by the dead-nettle. Its cousin, the stinging- 
nettle, belongs to a poisonous family, and is well 
protected by “stinging hairs.” Grazing animals 
through ages of experience have learned to give it 
a wide berth! The dead-nettle, on the other hand, 
is quite harmless; but it so closely mimics its evil- 
famed relative as to share in the latter’s immunity! 
The horehound, also, shows its wisdom by mimick- 
ing the well protected stinging-nettle. This, how- 
ever, seems no more astonishing than the curious 
resemblance certain seeds—like the maple, elm, ash, 
and sycamore—bear to the wings of evil-tasting 
moths and other insects. 
A striking example of mimicry is the pebble- 
briar, of the Philippine Islands. Its seeds are 
spherical in shape, and some have flat surfaces 
whose colour varies from a light sandy shade to a 
reddish brown. They not only imitate amazingly 
certain pebbles, but they actually give the appear- 
ance of stratification by small lines which circle 
them. 
Many and curious are the ways of Mother Na- 
ture for the protection of her offspring! 
