CH. VI.] THE FLOWEK. 187 



the footstalk ; and Mr. Knight succeeded, by inter- 

 grafting, in proving that the leaf-stalk, the tendril of 

 the vine, the fniit stalk, and the succulent point of 

 the annual shoot, may be substituted for each other — 

 a bunch of gTapes grew and ripened when grafted 

 upon the leaf-stalk ; and a succulent voung shoot of 

 the \me, under the same circumstances, acquired a 

 growth of many feet. 



The stamens are the only portion of a flower 

 which can be removed without preventing the form- 

 ation of fertile seed, and their loss must be sup- 

 plied by the introduction to the pistils of pollen 

 from some kindred flower. 



The calyx is not useless so soon as it ceases to 

 envelope and protect the flower, for the flower-stalk 

 continues increasing in size until the seed is per- 

 fected, but ceases to do so in those plants whose 

 caljTes remain long green if these be removed. On 

 the other hand, in the poppy, and other flowers 

 from which the calvx falls early, the flower-stalk 

 does not subsequently enlarge. 



The corulla or petals, with all their varied tints 

 and perfumes, have more important oSices to per- 

 form than thus to delight the senses of mankind. 

 Those bright coloiu's and their perfumed honey 

 serve to attract insects, which are the chief, and 

 often essential, assistants of impregnation ; and 

 those petals, as obsened by Linnaeus, sen-e as 



