FEB., 1912. MAMMALS OF ILLINOIS AND WISCONSIN CORY. 27 



TAXONOMY AND CLASSIFICATION. 



Taxonomy as applied to zoology is the science of arranging animals 

 in what is deduced from study of their morphological characters to be 

 their natural order or sequence and from which a system of classification 

 has been evolved. The necessity of some such an arrangement is suffi- 

 ciently obvious as to hardly require explanation, but I will quote the 

 words of Prof. Huxley in this connection, who says:* 



"It is possible and conceivable that every animal should have been 

 constructed upon a plan of its own, having no resemblance whatever to 

 the plan of any other animal. For any reason we can discover to the 

 contrary, that combination of natural forces which we term Life might 

 have resulted from, or been manifested by, a series of infinitely diverse 

 structures, nor would anything in the nature of the case lead us to sus- 

 pect a community of organization between animals so different in habit 

 and in appearance as a porpoise and a gazelle, an eagle and a crocodile, 

 or a butterfly and a lobster. Had animals been thus independently 

 organized, each working out its life by a mechanism peculiar to itself, 

 such a classification as that now under contemplation would be obvious- 

 ly impossible; a morphological or structural classification plainly im- 

 plying morphological or structural resemblances in the things classified. 

 As a matter of fact, however, no such mutual independence of animal 

 forms exists in nature. On the contrary, the members of the animal 

 kingdom, from the highest to the lowest, are marvellously connected. 

 Every animal has something in common with all its fellows; much, with 

 many of them; more, with a few, and usually so much with several, that 

 it differs but little from them. 



" Now a morphological classification is a statement of these grada- 

 tions of likeness which are observable in animal structures, and its 

 objects and uses are manifold. In the first place it strives to throw our 

 knowledge of the facts which underlie, and are the cause of, the similar- 

 ities discerned, into the fewest possible general propositions, subordinate 

 to one another, according to their greater or less degree of generality; 

 and in this way it answers the purpose of a memoria technica, without 

 which the mind would be incompetent to grasp and retain the multi- 

 farious details of anatomical science. But there is a second and even 

 more important aspect of morphological classification. Every group 

 in that classification is such in virtue of certain structural characters, 

 which are not only common to the members of the group, but distinguish 

 it from all others; and the statements of these constitute the definition, 

 of the group." 



* Huxley, T. H. Introd. Classif. of Animals, London, 1869, pp. 2-3. 



