NATURAL SCIENCES OF PHILADELPHIA. 115 



There are clearly recognizable characters distinguishing the two primary 

 divisions, or first duality of natural productions, organic and inorganic bodies, 

 or, as Linnaeus judiciously terms them, corpora organisata and corpora con- 

 pesta, and all the subordinate groups and species of either, necessarily possess 

 characters in common, though exhibiting themselves in degrees of modifica- 

 tions vastly diversified and numerous. In the former, or great organic di- 

 vision, the definition of the common characters are of course implied in the 

 term organic, and on the degrees and modifications of organization, whether 

 indicating what may be termed higher or lower development ; whether clearly 

 marking or only obscurely indicating inferior groups of whatever grade or 

 value ; or whether presenting very prominent or very obscure modifications, 

 with or without apparent object or relations on these degrees or modifica- 

 tions of organization or structure rest all classification, and all the great pri- 

 mary facts of independent existences, as presented to the human faculties, 

 whether of observation or reason. We hold it to be altogether probable, and 

 perhaps demonstrable, that all groups, of whatever grade or position, possess 

 positive or relative characters dependent on, and exponating their degree of 

 organization, and which characters absolutely establish and advertise then- 

 status in Nature. We hold, too, that all such groups admit of description, 

 and equally absolute or relative definition in language. Such is, and has 

 always been, the practical faith of naturalists, whatever their theories, the 

 accuracy of their observations, the extent and precision of their knowledge, 

 or their deficiencies in either, and this faith is very probably quite truthful, 

 and immutably founded on one important aspect of the relations of the ex- 

 ternal universe to the human mind, mutually questioning and responding, 

 calling to each other and answering gladly, as it were, like an echo. All the 

 processes of naturalists, systematic or descriptive, are based on the assump- 

 tion of the practicability of definition, and of groups, and of species alike. 

 Any other course, or any other assumption, would be assuredly unreasonable 

 and illogical, and destructive to the advancement of knowledge and of science. 

 " We must trust the perfection of the Creation so far," says a distinguished 

 author, " as to believe that whatever curiosity the order of things has awak- 

 ened in our minds, the order of things can satisfy." (Nature, an Essay, by 

 R. W. Emerson.) 



The organization of all beings, of which life is the essential character, seems to 

 present three very distinct grades or specializations of development, and ap- 

 parently indicates a classification based on such specialized development or 

 the characteristic organs and functions of each grade. In our opinion the 

 specialized organs and functions in each of these grades of development 

 present sufficient and exclusive characters, admitting of being defined 

 and applied readily as the real characteristics of three great primary di- 

 visions or kingdoms of Nature. The term, specialized, has been used by 

 Professor Owen with reference to the two kingdoms, Animal and Vegetable, 

 and in nearly the same sense that it is used by us. He says, most truly : 

 ''But the two divisions of organisms, called 'plants' and 'animals,' are 

 specialized members of the great natural group of living things." (Palaeon- 

 tology, p. 4.) The three great groups which we hold to be the primary di- 

 visions or kingdoms of organic life, present, essentially as characters or spe- 

 cializations of development, the prominence, or dominant prevalence of the 

 Reproductive System, the Nutritive System and the Nervous System and their 

 functions. 



The organs and corresponding functions which seem to characterize these 

 three kingdoms, and to become specialized and dominant in the organization 

 of each, are as follows : 



1. Organs for the continuation of the species, the function of which is Re- 

 production. 



1863.] 



