THE CROWFOOT FAMILY. 167 



nectar can be found at its base. The whole arrangement 

 constitutes a simple and efficient device for protecting the 

 nectar, and, at the same time, leaving it accessible to visit- 

 ing insects. 



III. Stamens. How many? Are they all alike? In 

 what order do they ripen? Study under a lens the mode 

 of dehiscence of the anthers. It will usually be found 

 that such facts, apparently trivial, are really important. 

 In the present case, after the oldest stamens begin to 

 shed their pollen, some little time elapses before the 

 youngest ones are mature, thus ensuring a supply of 

 pollen for visiting insects several days in succession, and 

 insects climbing over the flowers can hardly fail to carry 

 pollen from one to another. 



IV. Pistils. Study these in flowers of different ages. 

 It will be an advantage to make longitudinal sections of 

 the flower. Notice 



1. The elongated axis, receptacle, on which the pistils 



are inserted. 



2. The shape of the pistils. Draw an enlarged outline 



of one. 



8. In those that have been properly sectioned the single 

 ovule. Examine the latter in still older specimens 

 and satisfy yourself regarding its form, point of 

 attachment, and direction taken in the ovary. 

 Compare mature fruits and seeds if they are to 

 be had. 

 Read Miiller, Fertilization of Flowers, p. 74 et seq. 



RELATIONSHIP. 



We have next to study some of the immediate relatives 

 of the early crowfoot. This may be done at the same 



