MUTUAL AFFINITIES OF ORGANIC BEINGS 37S 



are highly serviceable in exhibiting the close affinity between 

 ruminants and pachyderms. Robert Brown has strongly insisted 

 on the fact that the position of the rudimentary florets is of the 

 highest importance in the classification of the grasses. 



Numerous instances could be given of characters derived from 

 parts which must be considered of very trifling physiological im- 

 portance, but which are universally admitted as highly serviceable 

 in the definition of whole groups. For instance, whether or not 

 there is an open passage from the nostrils to the mouth, the only 

 character, according to Owen, which absolutely distinguishes 

 fishes and reptiles — the inflection of the angle of the lower jaw 

 in Marsupials — the manner in which the wings of insects are 

 folded — mere color in certain Algae — mere pubescence on parts of 

 the flower in grasses — the nature of the dermal covering, as hair 

 or feathers, in the Vertebrata. If the Ornithorhynchus had been 

 covered with feathers instead of hair, this external and trifling 

 character would have been considered by naturalists as an im- 

 portant aid in determining the degree of affinity of this strange 

 creature to birds. 



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 history. 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 prevalence, 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 important, 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 Malpighiaceae 

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

 has remarked, "The greater number 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, de- 

 parting so wonderfully in a number of the most important points 

 of structure from the proper type of the order, yet M. Richard 



