['si* of Petals. 159 



In this investigation he has been successful, so that 

 most of the plant machinery is now understood in 

 its relations to the individual plant, and to the suc- 



f plants. 



\Yho doubts the use of the root and leaf in taking 

 up and elaborating nutriment for the plant? Who 

 doubts the use of the anther in producing pollen, 

 or of the p"llen grains in fertilizing the seed? Al- 

 though we may be uncertain about the use of 

 some parts, it does not affect the certainty of our 

 kii". ing those we have mentioned. 



T the use of the plant. Let us push 

 our inquiries further, and see if we can find in the 

 f the plant any contrivances, or in its 

 deu iv variations of form, not required 



by the economy of the plant itself. We omit for 

 the present all di> . as to the method by 



which t re prodl how they came to 



.ply inquire if there are such. For what 

 purpose are th of the flower, the crown of 



beauty to the plant ? Certainly they are not abso- 

 lutely essential in the production of seed, for many 

 plants are without them. And if in any case they 



deemed essential, certainly the beautiful pattern 

 of the petal, its numberless modifications and deli- 

 cate tints, adjusted with masterly accuracy, are not 

 necessary parts in the economy of plants. Of what 

 to the plant is that row of sterile flowers that 



i ns so many of our composites, the Rudbeckias, 

 and helianths ; or that curious circle of sterile 

 flowers bordering the cymes of hydrangeas and 



