AUGUST. 389 



wards 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 

 producing a cross which could not otherwise be eff'ected. 



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 dafl'odil and the white 

 lily arc 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 those of the ambrosia and mignonette, of the 

 grape vine, and of many of the amentaceous trees and shrubs. 

 With respect to flowers of an inconspicuous and greenish 

 hue, it is worthy of notice that they are seldom solitary, 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 

 upon 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 comparative 

 obscurity. Nature compensates them by giving them a large 

 and attractive flower, or one that is very sweetly scented. 

 The vines of the squash and the pumpkin, whose broad 

 leaves might conceal their flowers, bear them of extraordinary 

 size ; and the passion flower is formed with the most beautiful 

 arrangement of parts and variety of colors to render it con- 

 spicuous. The same is true, in a less degree, of the convol- 

 vulus and the bignonia. The Mexican vine and some of the 

 honeysuckles, on the contrary, having less conspicuous flowers, 

 receive their compensation by being endowed with an extraor- 

 dinary amount of fragrance. 



