0LA88IFI0ATI0N. 433 



The importance, for classification, of trifling characters, 

 mainly depends on their being correlated with many other 

 characters of more or less importance. The value indeed 

 of an aggregate of characters is very evident in natural his- 

 tory. Hence, as has often been remarked, a species may 

 depart from its allies in several characters, both of high 

 physiological importance, and of almost universal preva- 

 lence, and yet leave us in no doubt where it should 

 be ranked. Hence, also, it has been found that a 

 classification founded on any single character, however 

 important that may be, has always failed; for no part of 

 the organization is invariably constant. The importance 

 of an aggregate of characters, even when none are impor- 

 tant, alone explains the aphorism enunciated by Linnaeus, 

 namely, that the characters do not give the genus, but the 

 genus gives the character; for this seems founded on the 

 appreciation of many trifling points of resemblance, too 

 slight to be defined. Certain plants, belonging to the 

 Malpighiacese, bear perfect and degraded flowers; in the 

 latter, as A. de Jussieu has remarked, " The greater num- 

 ber of the characters proper to the species, to the genus, 

 to the family, to the class, disappear, and thus laugh at 

 our classification." When Aspicarpa produced in France, 

 during several years, only these degraded flowers, depart- 

 ing so wonderfully in a number of the most important 

 points of structure from the proper type of the order, yet 

 M. Eichard sagaciously saw, as Jussieu observes, that this 

 genus should still be retained among 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 allo- 

 cating 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 number, they use it as of 

 subordinate value. This principle has been broadly con- 

 fessed by some naturalists to be the true one; and by none 

 more clearly than by that excellent botanist, Aug. St. 

 Hilaire. If severa,! trifling characters are always found in 

 combination, though no apparent bond of connection can 

 be discovered between them, especial value is set on them. 



