266 



NATLKAL HISTORY ( »F TllH FARM 



arrangement is doubtless n\ost convenient for the visitors; 

 it is the one niDst coniinonly 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 oiTensive spines, or glandular hairs. The 



nectar of certain 

 trumpet-like con- 

 \( )l\-ulus flowers can 

 be sucked only by 

 long-tongued hum- 

 ming-bird moths. 

 That in the tightly- 

 closed bilabiate 

 corollas on themon- 

 kc}--flowers can be 

 had only by bum- 

 blebees, having 

 strength to o])en 

 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 \'isitors of many sorts. 

 The colors of summer flowers are in themselves very 

 beautiful and satisfying. Their fonns are wonderfully varied 

 and interesting. But colors and forms are alike increasingly 

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

 hfe. And we shall enjoy our coutnct with natuie better 



Pig. 107. Beard-tongue {Pentstemon pubescens) a, the 

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

 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 this stamen shakes pollen from the others 

 down upon its own back. (From the author's 

 "General Biology.") 



