OCTOBEE 14, 1898.] 



SCIENCE. 



515 



rational provisions for the incorporation of new 

 facts into systems of classification. At present 

 each of these lays its claim to a finality which 

 all past experience declares elusive. 



Under the method of types we shall also be 

 emancipated from the notion that all the species 

 of a genus must of necessity possess a certain 

 character or set of characters, and rational 

 methods of description may be introduced. 

 Natural groups are to be recognized and 

 pointed out not only by means of an absolute 

 agreement among their components, but also 

 from the coherence of the parts. A natural 

 genus may frequently be best distinguished 

 from its neighbors on different sides by different 

 characters, and the attention of the careful 

 naturalist is directed toward the discovery and 

 indication of the separating chasms as of the 

 greatest importance in generic demarcation. 

 Under the method of concepts the existence of 

 genera without absolute definitions cannot be 

 consistently admitted, but the method of types 

 renders their stable designation entirely prac- 

 ticable. 



Because it is philosophically true that we 

 know things only from their characteristics, it 

 does not follow that the set of formal characters 

 by which we attempt to describe a generic 

 group need be looked upon as the genus, since 

 genera do not exist because their species 

 agree in the few characters touched upon in the 

 description, but because they agree in all ex- 

 cept the superficial or quantitative specific dif- 

 ferences. Thus, until a group of organisms is 

 thoroughly known, the work expended on 

 elaborate generic definition is largely wasted, 

 each accession of new forms requiring an ex- 

 tensive readjustment. Under the method of 

 types the energy spent on these temporary con- 

 trivances could be applied in the interest of a 

 wider knowledge of the group, and that on a 

 permanent basis. A revision of the genera of 

 an order or family would consist in the thorough 

 description and graphic reproduction of typical 

 species rather than in the rehashing of con- 

 cepts. Differences between naturalists cannot 

 be expected to cease until knowledge becomes 

 complete, but with the attention directed to the 

 type rather than to the concept there would be 

 the important advantage of a fixed and definite 



point where all is now uncertain and fleeting. 

 The question of recognition of two related 

 genera would depend on whether the two sup- 

 posed series or groups of species really stand 

 apart, that is, whether there is a break between 

 them. Nomenclatorially the difficulty is re- 

 duced to a minimum. If I recognize one genus 

 the name is A — described in 1820 ; if two the 

 second is B — described at a later date. If half 

 the effort spent in arranging discarded concepts 

 had been applied to the better description of 

 types our knowledge of genera would be far in 

 advance of the present. The amount of futile 

 labor in systematic biology is appalling, and its 

 practical results are to hamper the naturalist 

 and to close the door of many departments of 

 the science against all who have not a large 

 amount of time for preliminary study of books 

 with little relation to present knowledge or 

 views of classification. Changes of names ren- 

 der the transition from popular to technical 

 literature very difficult, and some considerate 

 systematists have on this account opposed 

 further alterations, even when logically re- 

 quired. Under the method of types it would be 

 possible to select for the illustration of general 

 and popular works species whose systematic 

 standing is of assured permanence. 



These are some of the practical benefits 

 which would flow from the application of the 

 method of types, in addition to a nomencla- 

 torial stability out of the question under the 

 method of concepts. Many active systematists 

 are already using various modifications of the 

 suggested method, but its consistent and thor- 

 ough application under any uniform rule which 

 would eliminate the variable factor of indi- 

 vidual judgment, preference or prejudice is ap- 

 parently barred by the fact that extensive 

 initial changes in nomenclature would be neces- 

 sary. That many carelessly applied names 

 have escaped into popular use is not, however, 

 a good reason why systematic biology should 

 be kept permanently in its present confusion. 

 The vast majority of names are known, as yet, 

 only to systematists, and the next generation 

 can learn new ones as readily as old, while 

 present workers can well afford an occasional 

 changed designation in consideration of the 

 practical advantages of the method of types. 



