THE PEA FAMILY. 179 



5. Finally, with a number of perfect specimens of dif- 

 ferent ages, study the whole mechanism. Write 

 a complete account of the structure of the flower 

 and the mechanical arrangements favoring cross- 

 fertilization, making outline sketches whenever 

 it is necessary to render the description more 

 intelligible. 1 



RELATIONSHIP. 



As the flowers of different plants belonging to the pea 

 family are to be had, compare their structure and mech- 

 anism with those of the lupine. Any of the species 

 named above, the common locust for example, in flower a 

 little later than the lupine, will present interesting points 

 for comparison. 



1. Do corresponding whorls of the flowers of different 

 species agree as to position, form, and number of parts ? 



2. Is the mechanism by which fertilization is accom- 

 plished essentially the same as in the lupine ? 



3. In specimens that are past flowering, study the fruit 

 in early and later stages of development. 



4. Observe the position and form of the ovules, and, 

 in older specimens, the mode of clehiscence of the fruit. 



5. Aside from characters drawn from flowers and fruit, 

 determine whether leaves of the different species present 

 any common features. 



6. Summarize the results of your comparative study in 

 a brief statement of the characters common to those mem- 

 bers of the Leguminosa3 that you have become acquainted 

 with. 



1 Cf. Miiller's account of Lupinus luteus, the structure of which is 

 much like that of Lupinus per ennis. Fertilization of Flowers, p. 187. 



