COMPOUND ILOWKItS. 312 



too grrat v'o'eace to Nature, and swerN ii)g 

 fro^ii that beautiful and philosophical Liii- 

 n-' au priiiciple, of characterizing genera by 

 the fructi .cation alone; a piinciple which 

 those who are competent to the subject at 

 all, will, I beheve, never find to fail. The 

 seeds and flowers of the umbelliferous family 

 are quite sufficient for our purpose, while the 

 involucrum is very precarious and change- 

 able ; often deficient, often immoderately . 

 luxuriant, in the same genus. In the cymose 

 plants every body knows the real parts of 

 fructification to be abundantly adequate, the 

 Involucrum being of small moment ; witness 

 that most natural genus Cum us. For all 

 these, and other reasons, to particularize 

 which would lead me too far, I have, p, 256, 

 reckoned the Umbel and Cvme modes of 

 flowering, and iiot themselves aggregate 

 flowers, 



