DEFENCES OF PLANTS 339 



floral leaves act as an umbrella. The flowers of the 

 Lime-tree are protected by foliage leaves; raindrops 

 roll off their edges and do liot reach the sheltered 

 flowers. A member of the Buttercup family, the Globe- 

 flower {TrolUus Europceus), produces blooms which never 

 open so as to display their essential organs; the floral 

 leaves curl over and form a yellow ball. Bees can 

 push their way in to the concealed organs and leave 

 the flower without much trouble, but raindrops are 

 turned aside. 



A cordial welcome and a reward are offered to polli- 

 nating insects, but an insect which attempts to steal 

 honey without giving a quid pro quo is most unwelcome. 

 Among the defensive arrangements which are calculated 

 to thwart these burglarious intruders are hairs and 

 sometimes sticky secretions. Honey-stealers which 

 crawl up the stems of some members of the Campion 

 family in the hope of securing honey through the back- 

 door, so to speak, on nearing the flowers find themselves 

 caught by a viscid secretion which effectually bars their 

 progress and, in most instances, causes their death. 

 The sticky fluid is secreted by hairy glands, and is said, 

 in some cases, to capture marauders in order that they 

 may be afterwards digested. It is not unlikely that in 

 the plants referred to, notably the Catchflies, and also 

 in the Rue-Leaved Saxifrage {Saxifraga tridactylites) and 

 the Hairy Stonecrop {Sedwm villoswm), we have in- 

 stances of an early stage in the development of the car- 

 nivorous habit. What, indeed, would be more econom- 

 ical than that a captured marauder should be turned 

 to account as food ? The Wild Teazle {Dipsacus syl- 

 vestris) is well armed against insect-bandits as well as 



