478 NATURAL HISTORY OF MAN. 



all have concurred to this end. Other sciences, moreover,, 

 and especially geology, have lately furnished new aids to this 

 branch of knowledge. What space is to the astronomer, time 

 is to the geologist vast beyond human comprehension, yet 

 seen and comprised by the conclusions of the science. The 

 astronomer indeed throws his line of numbers more boldly 

 and securely into the depths of the infinite before him. The 

 geologist can rarely give this mathematical certainty to his 

 subject, or express the vastness of time more definitely than 

 by the relation and succession of periods. But this result, 

 and the methods by which it is attained, are such as well 

 attest the grandeur of the science. The study of fossil 

 remains, in representing successive epochs of change, and re- 

 newed creations of organic life on the surface of the globe, 

 becomes the interpreter of facts of transcendent interest. 

 What more wonderful than to extricate from the depths of 

 the earth those mute yet expressive evidences of time far 

 anterior to the creation of Man ! of ages to which no 

 human estimate can ascend, save as respects the mere order of 

 succession in the series ! What nearer material approach can 

 man find to his Maker, than in deciphering these successive 

 modifications of animal life, which, while still including its 

 simpler forms, gradually acquire higher types of organisation, 

 and express a scheme of constant progress, however imperfect 

 our view of the steps through which it is made ? Dividing 

 these periods by the geological characters which so clearly 

 denote their relative age and succession, and the altered 

 conditions of the earth in each, we may affirm that each 

 period, amidst a general change of species, contains some 

 element of higher life and more consummate organisation. 

 We have not room to dwell on this topic, or to detail the 

 different expressions which naturalists have given to the 

 general fact; but its bearing upon our subject the natural 

 history of Man will be obvious at first sight, and rises in 

 importance as we pursue and enlarge the enquiry. 



