Chap. XIV.] CLASSIFICATION. 209 



that a classification founded on any single character, 

 however important th^t may be, has always failed; for 

 no part of the organisation is invariably constant, 

 ihe importance of an aggregate of characters, even 

 when none are important, alone explains the aphorism 

 enunciated by Linnaeus, namely, that the characters do 

 not give the genus, but the genus gives the characters; 

 for this seems founded on the appreciation of many 

 trifling points of resemblance, too slight to be defined. 

 Certain plants, belonging to the Malpighiaceee, bear 

 perfect and degraded flowers; in the latter, as A. de 

 Jussieu has remarked, " the greater number of the char- 

 acters proper to the species, to the genus, to the family, 

 to the class, disappear, and thus laugh at our classifi- 

 cation." When Aspiearpa produced in France, during 

 several years, only these degraded flowers, departing 

 so wonderfully in a number of the most important 

 points of structure from the proper type of the order, 

 yet M. Richard sagaciously saw, as Jussieu observes, 

 that this genus should still be retained amongst the 

 Malpighiaceae. This case well illustrates the spirit of 

 our classifications. 



Practically, when naturalists are at work, they do 

 not trouble themselves about the physiological value 

 of the characters which they use in defining a group 

 or in allocating any particular species. If they find 

 a character nearly uniform, and common to a great 

 number of forms, and not common to others, they use 

 it as one of high value; if common to some lesser num- 

 ber, they use it as of subordinate value. This principle 

 has been broadly confessed by some naturalists to be the 

 true one; and by none more clearly than by that ex- 

 cellent botanist, Aug. St. Hilaire. If several trifiing 



