416 SYSTEMATIC BOTANY, OR 



Section 2 — Natural Systems of Classification. 



The object of all natural systems, as already noticed (see 

 page 405), is to group together those plants which correspond in 

 the greatest number of important characters, and to separate 

 those that are unlike. The mode in which this has been at- 

 tempted to be carried out, varies according to the particular 

 views of botanists as to the relative value of the characters 

 furnished by the different organs of plants ; hence it will be 

 necessary for us, before proceeding to describe the more im- 

 portant natural systems, to make some remarks upon this 

 subject. The observations of Dr. Lindley upon this head are 

 so much to the point, that we cannot do better than quote them, 

 although it Avill be afterwards seen, that we venture, in accord- 

 ance with the views of many other botanists, to differ in some 

 particulars from that celebrated systematist. 



" The only intelligible principle by which to estimate the 

 respective value of the characters furnished by the different 

 organs is according to their known physiological importance; 

 regarding those organs of the highest rank which are most 

 essential to the life of the plant itself; placing next in order 

 those with which the plant cannot dispense if its race is to be 

 preserved; assigning a still lower station to such organs as may 

 be absent without considerable disturbance of the ordinary func- 

 tions of life; and fixing at the bottom of the scale those parts, 

 or modifications of parts, which may be regarded as accessory, 

 or quite unconnected with obviously important functions. 



"The first office which all organised beings have to perform is 

 that of feeding, for it is thus only that their existence is main- 

 tained. The second is that of propagating, by means of which 

 their species is perpetuated. These being functions of the 

 highest importance, it is reasonable to conclude that the organs 

 provided for their pro])er execution must be of the highest im- 

 portance also, and hence that they are, beyond all others, 

 valuable for the purposes of classification. And, again, be- 

 cause tlie power of feeding must come before that of propa- 

 gating, it miglit be conjectured beforehand, that the organs 

 destined for the former operation would aff'ord the first elements 

 of a natural method. But since the act of feeding is very 

 simple in the Vegetable Kingdom, because of the similar modes 

 of life observable among i)lants, while, on the contrary, the act 

 of pro])agation is highly diversified, on account of the very 

 varied nature or structure of the parts by which it is accom- 

 plished; so might we conjecture that the organs of nutrition 

 would afford but few distinctions available for purposes of 



