Natural History 627 



The leaves of nettles, etc., have stinging hairs or bristles as 

 protection against the attacks of large herbivorous animals. The 

 stinging hair plays an important part, as it penetrates the skin 

 and injects into the wound a poison which causes the painful 

 "burning" sensation. 



In the cactus-like plants the variety of weapons is consider- 

 able. A single species often bears three or four kinds of weapons. 

 They are armed with large spines and small bristles, short, 

 thick and thin, knotty and smooth, straight-pointed and barbed. 

 And so by thorns, spines, and prickles, plants often protect 

 themselves. 



The nectar of some flowers intoxicates the bees, who are 

 believed to acquire a taste for it. In his Botany of To-day, Pro- 

 fessor Scott Elliott describes a well-known orchid which has a 

 hinged lip: 



When the unsuspecting insect enters the flower and 

 passes over the lip, it is suddenly jerked forward and thrown 

 into a sort of bath of liquid; as it painfully crawls out, with 

 wetted wings, it has to carry away the pollen masses, and so 

 effect pollination. There is no cruelty in this, for the insect 

 is supposed to visit another flower and cannot be much 

 harmed. 



9 



HOW PLANTS ARE REPRODUCED 



In that great burst of activity in spring which heralds the 

 approach of warmer weather, plants make an irresistible appeal 

 to the eye. We welcome the clear colours of the snowdrop, celan- 

 dine, and violet, and still more the bursting bud and shooting 

 blade covering the earth with a hundred delicate shades of green. 

 The tree unfolds its leaves, and root-stock and bulb push up new 

 shoots through the soil; such plants wake from their annual rest 

 and embark again on an active period. Among them arise myriads 

 of seedlings, new plants growing from germinating seeds ; in these 



