180 



THE PLANT WOKLU. 



dilated, spreading and reflexed, while the three inner segments are nsnally 

 narrower, though sometimes nearly as broad as the outer ones. Usu- 

 ^ ally they are erect and form a more or less closed 



dome over the other parts of the flower. Theie 

 are three stamens, one before each outer perianth 

 segment. The style is divided into three petal- 

 like branches which arch oxgv the stamens and 

 bear the stigmas immediately under these mostly 

 two-lobed tips. 



A section through a fiower of Ii-la pmuUa is 

 shown in figure 1. In this a. a. are outer 

 perianth segments, h. inner segments, c. a 

 stamen, and d. d. parts of two style- branches with 

 the stio:ma at e. It will be seen that the stigma 



Fig. \.—Ins imviila. 



forms a shelf-like plate 

 above the anther, and as 

 the latter faces outward 

 it is impossible for the 

 pollen to reach the 

 stigma without aid. 

 But in this we see an 

 admirable adap t a t i o n 

 for the conveyance of 

 the pollen by insects. 

 A bee, standing on the 

 only landing place, the 

 reflexed sepal, thrusts 

 its head down below the 

 anther in searching for 

 nectar, and on remov- 

 ing it carries ofi^ some 

 of the pollen on its back 

 which is scraped off by 

 the stigma of the next 

 flower visited. 



It is perhaps hard- 

 ly necessary to say that ^^^- 2.-/«'-^ a-istata 

 Irises grow in a variety of situations from dry sand to swamps and 

 river-banks. Thus the little Irh verna and /. cthtata [see figure 2] 



