CHAPTER XII 



TAXONOMY 



Taxonomy (from the Greek taxis = arrangement and nomos = law) is 

 literally an orderly arrangement. As applied to living things it refers 

 to the classification of animals and plants on the basis of fundamental 

 similarities. The taxonomy of animals, with which this chapter deals, 

 is wholly distinct, except in principle, from that of plants, though the 

 simplest members of the plant and animal kingdoms are not readily dis- 

 tinguishable from one another. Zoological taxonomy is often called sys- 

 tematic zoology. 



Conceptions of Taxonomy. — An orderly arrangement of objects or 

 facts presupposes a system of classification, and the same objects or 

 facts can usually be classified in different ways by the use of different 

 characters, qualities or relations as a basis. Moreover, different systems 

 of classification may be adopted to suit particular purposes or to satisfy 

 particular bents of mind. Thus because it is possible to classify animals 

 in different ways, taxonomy has often been considered a mere cataloging 

 of animal forms, and it has been assumed that the purpose of taxonomy 

 is merely to find a way in which the forms may be conveniently arranged, 

 described and cataloged. This conception is erroneous, but to state 

 wherein lies the error requires that the aims of those who propose the 

 various systems be compared. Much of this comparison must await 

 the historical account below. It may be pointed out here, however, that 

 all but one of the systems of classification that have ever been in use 

 have been essentially devices to save confusion. Things were put upon 

 shelves, figuratively, and labeled and cataloged and perhaps cross- 

 cataloged. So long as prevention of confusion was the chief aim, it made 

 little difference whether the shelves were numbered in vertical columns 

 or in horizontal rows. Every classification which sought nothing more 

 than convenience might therefore be artificial and arbitrary, and one 

 person's classification might be quite as good as another's. The one 

 exception to this arbitrary basis of arrangement is found in the system 

 of classification that prevails at the present time. The modern system 

 serves two purposes, instead of but one. It has grown up largely since 

 the general acceptance of the evolution doctrine, according to which 



260 



