THE CHARACTERS OF GENERA. 129 
the Corals. Many others have followed this ex- 
ample, but few have kept in view the necessity of 
a uniform mode of proceeding, or, if they have 
done so, their researches have covered too limit- 
ed a ground to be taken into-consideration in a 
discussion of principles. 
It is, in fact, only when extending over a 
whole Class that the study of Genera acquires a 
truly scientific importance, as it then shows, in a 
connected manner, in what way, by what features, 
and to what extent a large number of animals 
are closely linked together in Nature. Con- 
sidering the Animal Kingdom as a single com- 
plete work of one Creative Intellect, consistent 
throughout, such keen analysis and close criti- 
cism of all its parts have the same kind of inter- 
est, in a higher degree, as that which attaches to 
other studies undertaken in the spirit of careful 
comparative research. These different categories 
of characters are, as it were, different peculiari- 
ties of style in the author, different modes of 
treating the same material, new combinations of 
evidence bearing on the same general principles. 
The study of Genera is a department of Natural 
History which thus far has received too little at- 
tention even at the hands of our best zodlogists, 
and has been treated in the most arbitrary man- 
ner ; it should henceforth be made a philosophical 
investigation into the closer affinities which nat- 
6* I 
