Genera of the Family Attidce. 259 



are always some properties common to all things which are 

 included. Others there often are, to which some things, 

 which are nevertheless included, are exceptions. But the 

 objects which are exceptions to one character are not excep- 

 tions to another; the resemblance which fails in some par- 

 ticulars, must be made up for in others. The class, therefore^ 

 is constituted by the possession of all the characters which 

 are universal, and most of those which admit of exceptions. 

 If a plant had the ovules erect, the stigmata divided, pos- 

 sessed the albumen, and was without stipules, it possibly 

 would not be classed among the Rosacese. But it may want 

 any one, or more than one, of these characters, and not be 

 excluded. The ends of a scientific classification are better 

 answere:^ by including it. Since it agrees so nearly, in its 

 known properties, with the sum of the characters of the 

 class, it is likely to resemble that class more than any other 

 in those of its properties which are still undiscovered." 



A further confusion has arisen from certain authors mak- 

 ing their generic definitions descriptive rather than compar- 

 ative. For example, the definition of the genus Maratus 

 Karsch is doubtless a good description, so far as it goes, of 

 the species for which the genus was formed, and yet is 

 equally applicable to many other genera, and in no way 

 assists in organizing knowledge, nor in facilitating identifi- 

 cation, which should be the two-fold purpose of a classifica- 

 tion. 



The synonymy of the genera is only partial; and those 

 who have had most experience in the difiiculties of this 



lizard are reptiles. You see he does class by type, and not by definition. 

 But how does this classification differ from that of the scientific zoolo- 

 gist? how does the meaning of the scientific class-name of "Mammalia" 

 differ from the unscientific of " B3a3t3?" Why, exactly because the for- 

 mer depends on a definition, the lat'.er on a type. The class Mammalia is 

 scientifically defiled as "all animals which have a vertebrated skeleton 

 and suckle their young." Here is no reference to type, but a definition 

 rigorous enough for a geometrician, and such is the character which every 

 scientific naturalist recogcizes as that to which his classes must aspire — 

 knowing, as he does, that classification by type is simply an acknowledg- 

 ment of ignorance and a temporary device." Educational Value of Nat- 

 ural History Sciences; Lay Sermons, Addresses and Reviews, pp. 82, 83. 



