THE LILY FAMILY. 169 



rilla, etc., and, among vegetables, the onion, asparagus, 

 and some others. The extraordinary extent to which the 

 vegetative organs have been modified, as illustrated by 

 the cladophylls of asparagus and Ruscus, indicate a com- 

 paratively remote origin, notwithstanding the relative sim- 

 plicity of the flowers, some of which, however, as the 

 Yucca, exhibit very remarkable relations to insects. 



The student is advised to extend his acquaintance to as 

 many genera as possible, and to follow as far as opportunity 

 offers, the transitional stages through which it is believed 

 that the more highly developed ones have passed.^ See 

 Miiller's admirable review of the Liliacese, Fertilization of 

 Flowers, pp. 558, 559, and the papers of Riley and Trelease, 

 third and fourth annual reports of the Missouri Botanical 

 Garden, 1892 and 1893. 



SPECIAL STUDIES. 



I. Modified stems occurring in the Liliacese. 

 II. Adaptations to fertilization by the aid of insects as 



exhibited by different genera. 

 III. Evidence regarding progressive evolution on the 

 one hand, and degeneration on the other, with 

 the Liliacese as a point of departure. 



1 A number of interesting points for comparison will present them- 

 selves as the family is studied, e.g., — 



1. The nectaries, which vary much in different genera. 



2. Bulblets produced in the axils of the leaves of Lilium. 



3. Wide differences of underground stems. Contrast the creeping 

 rootstock of Smilacina, Medeola, etc., with the bulb of Lilium and Soilla. 



