296 BAIN ON THE EMOTIONS AND THE WILL. 



the history of classification is also to be noted. Very fre* 

 quently the kinship of an organism cannot be made out 

 even by exhaustive analysis, if that analysis is confined to 

 the adult structure. In many cases it is needful to ex- 

 amine the structure m its earlier stages ; and even in its 

 embryonic stage. So difiicult was it, for instance, to de- 

 termine the true position of the Cirrhipedia among animals, 

 bj examining mature individuals only, that Cuvier errone- 

 ously classed them with Mollusca, even after dissecting 

 them ; and not until their early forms were discovered, 

 were they clearly proved to belong to the Crustacea. So 

 important, indeed, is the study of development as a means 

 to classification, that the first zoologists now hold it to be 

 the only absolute criterion. 



Here, then, in the advance of natural-history-classifica- 

 tion, are two fundamental facts, which should be borne in 

 mind when classifying the emotions. If, as Mr. Bain right- 

 ly assumes, the emotions are to be grouped after the natu- 

 ral-history-method ; then it should be the natural history- 

 method in its complete form, and not in its rude form. 

 Mr. Bain will doubtless agree in the position, that a cor- 

 rect account of the emotions in their natures and relations, 

 must correspond with a correct account of the nervous 

 system — must form another side of the same ultimate facts. 

 Structure and function must necessarily harmonize. Struc- 

 tures which have with each other certain ultimate connex- 

 ions, must have functions that have answering connexions. 

 Structures that have arisen in certain ways, must have func- 

 tions that have arisen in parallel ways. ' And hence if anal- 

 ysis and development are needful for the right interpreta- 

 tion of structures, they must be needful for the right inter- 

 pretation of functions. Just as a scientific description of 

 the digestive organs, must include not only their obvious 

 forms and connexions, but their microscopic characters, 

 ani also the wiys in which they severally result by differ 



