FUNDAMENTAL RELATIONS OF ANIMALS 7 



we might arrive at this distinction by a careful investigation of that 

 single Articulate, as well as by the study of all of them; and we might 

 then recognize its type and ascertain its class characters as fully as if 

 the type embraced several classes, and these classes thousands of spe- 

 cies. Secondly, this animal has a form, which no one would fail to rec- 

 ognize; so that, if form can be shown to be characteristic of families, 

 we could thus determine its family. Again: besides the general struc- 

 ture, showing the fundamental relations of all the systems of organs 

 of the body to one another in their natural development, our inves- 

 tigation could be carried into the study of the details of that structure 

 in every part, and thus lead to the recognition of what constitutes 

 everywhere generic characters. Finally: as this animal has definite 

 relations to the surrounding world, as the individuals living at the 

 time bear definite relations to one another, as the parts of their body 

 show definite proportions, and as the surface of the body exhibits a 

 special ornamentation, the specific characters could be traced as fully 

 as if a number of other species were at hand for comparison; and they 

 might be drawn and described with sufficient accuracy to distinguish 

 it at any future time from any other set of species found afterwards, 

 however closely these new species might be allied to it. In this case 

 then we should have to acknowledge a separate branch in the animal 

 kingdom, with a class, a family, and a genus, to introduce one species 

 to its proper place in the system of animals. But the class would have 

 no order, if orders determine the rank, as ascertained by the compli- 

 cation of structure; for, where there is but one representative of a 

 type, there is no room for the question of its superiority or inferiority 

 in comparison to others within the limits of the class, orders being 

 groups subordinate to one another in their class. Yet even in this 

 case, the question of the standing of Articulata, as a type among the 

 other great branches of the animal kingdom, would be open to our 

 investigations; but it would assume another aspect from that which 

 it now presents, as the comparison of Articulata with the other types 

 would then be limited to the Lobster and would lead to a very differ- 

 ent result from that to which we may arrive, now that this type in- 

 cludes such a large number of most extensively diversified represent- 

 atives belonging even to different classes. That such speculations 

 are not idle must be apparent to any one who is aware that, during 



