COLORS AND FRAGRANCE OP FLOWERS. 83 



has finished his work. Such is the Asclepias. Certain 

 small insects enter the flower, and descend through a 

 sort of tube into a chamber containing the parts of fruc- 

 tification. They are immediately confined there by 

 little hairs bristling down towards the base of the 

 flower, that prevent their returning. The insect, made 

 restless by this confinement, moves about and covers 

 himself with pollen. The flower soon fades, when he 

 escapes, bearing this pollen to another flower, and pro- 

 ducing a cross which could not otherwise be effected. 



It may be observed that the most gaudy flowers have 

 in general the least odor; for just in proportion as they 

 are made attractive by their forms and by the splendor 

 of their hues, is their fragrance less needful to them. 

 Accordingly, white flowers are generally sweeter than 

 those of the same genus which are highly colored. 

 The white daffodil and the white lily are the sweetest 

 of their respective genera. The same is true of the 

 white tulip, which is, I believe, always fragrant. Some 

 of the most powerful odors are emitted by greenish 

 flowers, like {hose of the ambrosia and mignonette, of 

 the grape vine, and of many of the amentaceous trees 

 and shrubs. With respect to flowers of an inconspicu- 

 ous and greenish hue, it is worthy of notice that they 

 are seldom soMtary, but grow in dense clusters or spikes, 

 or upon trees where they are rendered apparent as a 

 part of the tree that bears them. In this way, also, we 

 may account for the fact that the flowers of trees are 

 not, in general, so beautiful as those which grow uponv 

 the ground, since the elevated position of the former 

 causes them to be more readily discovered by the insect.. 

 The flowers of twining plants, on the other hand, are 

 the largest in- existence. Their habit of creeping about 

 under the shade of trees and shrubs,, places them in 



