314 PLANT-LIFE 



radiating hairs bar the constriction, or neck. Now it 

 happens that the club of the spadix, when ripe, has a 

 most offensive odour, yet one which is particularly 

 attractive to a small fly (Psychoda). Numbers of these 

 flies visit the plant, and press their way down to the 

 enclosed inflorescence ; they can pass the radiating hairs, 

 which radiate with a downward inclination, on entering, 

 but once past this barrier they find themselves in a 

 chamber from which escape is temporarily impossible, 

 for flight is impeded by the downward-pointing hairs. 

 But the flies seem to offer no objection to their brief 

 imprisonment, for the victuals are good and plentiful. 

 The female flowers at the base of the spadix are the first 

 to ripen; they offer the flies some honey, which is not 

 despised, and the prisoners, in their eagerness to secure 

 the " fluid nectareous," dust the stigmas with pollen 

 brought from another plant, thus making fertilization 

 possible. In due course the stamens situated above the 

 pistils come to maturity, and powder the flies with 

 pollen. But how can the flies get to another inflores- 

 cence, seeing that the exit from their prison is barred ? 

 The difficulty is easily overcome. The hairs wither, and 

 the spathe droops; the erstwhile prison is a prison no 

 longer, and the flies are at liberty to carry their burden 

 of pollen to an inflorescence which, by its appearance 

 and odour, advertises the fact that it is ready for the 

 reception of visitors. 



But colour and scent are, generally speaking, sub- 

 sidiary attractions ; they may be regarded as advertising 

 agents calling the attention of desirable visitors to the 

 excellent food which is free for the fetching. They 

 make a proclamation concerning stores of sweetness, and 



