FAMILIES. 239 



their form from dogs or cats, or from seals and porpoises. 

 In this definite meaning, form corresponds also to what 

 we call figure when speaking of men and women; and it 

 is when taken in this sense that I would now consider the 

 value of forms as characteristic of different animals. We 

 have seen that form cannot be considered as a character 

 of branches, nor of classes; let us now examine further, 

 whether it is a character of species. A rapid review of 

 some of the best known types of the animal kingdom, 

 embracing well-defined genera with many species, will at 

 once show that this cannot be the case ; for such species 

 do not generally show the least difference in their forms. 

 Neither the many species of Squirrels, nor the true Mice, 

 nor the Weasels, nor the Bears, nor the Eagles, nor the 

 Falcons, nor the Sparrows, nor the Warblers, nor the genu- 

 ine Woodpeckers, nor the true Lizards, nor the Frogs, nor 

 the Toads, nor the Skates, nor the Sharks proper, nor the 

 Turbots, nor the Soles, nor the Eels, nor the Mackerels, 

 nor the Sculpins, nor the genuine Shrimps, nor the Craw- 

 fishes, nor the Hawkmoths, nor the Geometers, nor the 

 Dorbugs, nor the Spring-Beetles, nor the Tapeworms, nor 

 the Cuttlefishes, nor the Slugs, nor the true Asterias, nor 

 the Sea- Anemones, could be distinguished among them- 

 selves one from the other by their form only. There may 

 be differences in the proportions of some of their parts, 

 but the pattern of every species belonging to well-defined 

 natural genera is so completely identical that it will never 

 afford specific characters. There are genera in our system 

 which, as they now stand, might be alluded to as examples 

 contrary to this statement; but such genera are still based 

 upon very questionable features, and are likely to be 

 found, in the end, to consist of unnatural associations of 

 heterogeneous species: at all events, all recent improve- 



