BIQ AND LITTLE. 187 



these intensely minute microscopical creatures 

 and ourselves or the elephant every intermediate 

 stage exists, plants and animals shading oiT in 

 size to practically illimitable extents, from tlie 

 whale and the oak-tree down to the inlinitesinuil 

 objects which can hardly be distinguished by the 

 acntest eye with the very highest powers of the 

 best microscopes. 



Time affords us equal vistas of infinite dura- 

 tion and of infinitesimal subdivision. Our little 

 luunan life, our days and years, give us indeed no 

 l)roper standard for measuring the vast past ex- 

 tent of geolijgical ages. A man's utmost span, 

 even in cases like those of Sir Moses Montefiore 

 and ]\I. Chevreul the chemist, barely exceeds a 

 hundred years. But the glacial epoch, the very 

 newest of geological dates, lies behind us (accord- 

 ing to Doctor CroU's calculations) at a distance of 

 two hundred and forty thousand winters. Man 

 is now known to have existed on the earth for at 

 least that very lengthy period, and in all proba- 

 bility for much longer. But before the glacial 

 epoch began came the far longer pliocene age ; 

 and before that the yet longer miocene ; and 

 before that again the still more extended eocene. 

 All these were as mere single days in a long year 

 comi)arcd with the vast unmeasured extent of the 

 secondary age ; and the secondary age itself was 

 but a tiny fraction of the still more illimitable 

 primary period. Thus in time, as in space, the 



