192 MYSTERIES OF THE FLOWERS 



houses in which ants are happy to dwell a garri- 

 son always on the alert. In Guiana the orchids are 

 especially liable to attack, and some of them form 

 veritable barracks of their roots for an army of ants 

 to occupy. There are as many plant defences as 

 there are locks and safety-contrivances, guns and 

 fortifications, all to prolong life and make blooming 

 and seed-bearing possible, but there are special safe- 

 guards to protect the nectar and pollen. 



BURGLAR INSURANCE 



Besides crawling things, which may be stopped 

 by bristly stem or calyx, there are unwelcome guests 

 who arrive on the wing, and these are often balked 

 by a closed corolla, as we see in the snap-dragon and 

 closed gentian of our coloured plate, which are 

 accessible only to the bee. Again, some flowers 

 serve their nectar in shallow cups from which short- 

 tongued insects, only, can sip, whilst others conceal 

 their sweets in deep and narrow nectaries, accessible 

 to none but the long, prehensile tongues of moths 

 and butterflies 



RAIN SHELTERS 



While rain is most useful and necessary to the 

 growth of the plant, it is most harmful to the nectar 



