UNIFORMITY OF TYPE. 183 



tine, osteo-dentine, and enamel ; and had the parts been 

 less evanescent, or were chemistry more subtle to detect, 

 bone, cartilage, and flesh hair, wool, and horn scale, 

 feather, and claw, would be found to have been ever built 

 up of the same elements, and, family for family, in the 

 same proportions. 



So far as fossil evidence goes (and by that alone can 

 we be guided), the plants and animals of the ancient 

 world, though differing widely in genera and species, were 

 neither "abnormal" nor "monstrous," but both in point 

 of size, and form, and structural adaptations, were very 

 much alike to those of the present day. So much so, 

 indeed, that could we recall them to mingle in the busy 

 scene of life around us, they would neither startle us by 

 their appearance, nor alarm us by their habits, one whit 

 more than the existing Flora and Fauna of distant and 

 different regions. The great types remain the same through- 

 out all time and space ; and though the modifications have 

 been innumerable, these modifications, even in their aggre- 

 gate, have never amounted to an obliteration of any im- 

 portant primal distinction. Acrogenous, endogenous, and 

 exogenous radiate, articulate, molluscan, and vertebrate, 

 range side by side as distinctly now, each within its own 

 typical idea, as when they first clothed the land and peo- 

 pled the waters. The relations of a mathematical line, or 

 the unions of a chemical element, are not more fixed and 

 certain than the relationships of structural organisation. 

 This organ or that organ may be modified for the perform- 

 ance of some special function, and this modification may 

 imply a certain amount of variation in all the co-related 

 parts ; still the prime typical conception remains distinct 

 and essential under every condition of space, and through 

 every progressional mutation of time. 



" Nor is it only the plan of the great types," says Pro- 



