26.6 NATURAL HISTORY OF THE FARM 



arrangement is doubtless most convenient for the visitors; 

 it is the one most commonly adopted, and most successful. 

 And as there are groceries that cater to a select and limited 

 patronage, so there are flowers that put their nectar out of 

 reach of common visitors, and reserve it for those that 

 are epecially endowed not with long pocketbooks, but 

 with Icng proboscides. They secrete their nectar at the 

 bottom of deep and narrow corolla tubes or spurs, or behind 

 barriers of sharp offensive spines, or glandular hairs. The 



nectar of certain 

 trumpet-like con- 

 volvulus flowers can 

 be sucked only by 

 long-tongued hum- 

 ming-bird moths. 

 That in the tightly- 

 closed bilabiate 

 corollas on the mon- 

 key-flowers can be 



FIG. 107. Beard-tongue (Pentstemon pubescens) a, the i,_ J 

 flower; b, section of the same, showing the trigger- Ilclcl 

 like bearded upper stamen, which is declined so that 

 it overlies the stalks of the pollen-bearing stamens. 



The insect, entering where indicated by the arrow, +,.,,,. -*-!, .*-- 

 in clutching ttis stamen shakes pollen from the others MJcIlglll IU 



"G'enerTmo^y." ^ ^^ *" aUth r>S the mOUth of the 



corolla and enter. 



So, when we watch the flower-clumps in the fields, we shall 

 see but few visitors about such specialized flowers as turtle- 

 heads (fig. 103), and butter-and-eggs, while the outspread 

 tables of open corollas of such as meadowsweet (fig. 104) 

 and wild carrot are thronged with visitors of many sorts. 

 The colors of summer flowers are in themselves very 

 beautiful and satisfying. Their forms are wonderfully varied 

 and interesting. But colors and forms are alike increasingly 

 instructive when we learn what roll they fill in the drama of 

 life. And we shall enjoy our contact with nature better 



