6'2G UNITY OF DESIGN. 



followed the footsteps of Nature herself, who in 

 all her operations combines the apparently op- 

 posite principles of general resemblance, and of 

 specific variety ; so that the races which she 

 has united in the same group, though possessed 

 of features individually different, may easily be 

 recognised by their family likeness, as the off- 

 spring of a common parent. 



" Facies non omnibus una ; 

 Nee diversa tamen ; qualem decet esse sororum." 



We have seen that in each of the two great 

 divisions, or kingdoms of organic nature, the 

 same general objects are aimed at, and the same 

 general plans are devised for their accomplish- 

 ment; and also that in the execution of those 

 plans similar means and agencies are employed. 

 In each division there prevails a remarkable 

 uniformity in the composition and properties of 

 their elementary textures, in the nature of their 

 vital powers, in the arrangement of their organs, 

 and in the laws of their production and develope- 

 ment. The same principle of analogy may be 

 traced, amidst endless modifications of detail, in 

 all the subordinate groups into which each 

 kingdom admits of being subdivided, both in 

 respect to the organization and functions of 

 the objects comprehended in each assemblage, 

 whether we examine the wonders ©f their me- 

 chanical fabric, or study the series of processes by 

 ■which nutrition, sensation, voluntary motion, and 



