PROGRESS OF NATURAL HISTORY. 669 



can hardly look forward to the time when we 

 shall be in possession of it without shrinking 

 from the grandeur of our undertaking. The 

 past history of our science rises before me 

 with its lessons. Thinking men in every part 

 of the world have been stimulated to grapple 

 with the infinite variety of problems, con- 

 nected with the countless animals scattered 

 without apparent order throughout sea and 

 land. They have been led to discover the 

 affinities of various living beings. The past 

 has yielded up its secrets, and has shown them 

 that the animals now peopling the earth are 

 but the successors of countless populations 

 which have preceded them, and whose remains 

 are buried in the crust of our globe. Further 

 study has revealed relations between the ani- 

 mals of past time and those now living, and 

 between the law of succession in the former 

 and the laws of growth and distribution in 

 the latter, so intimate and comprehensive that 

 this labyrinth of organic life assumes the 

 character of a connected history, which opens 

 before us with greater clearness in proportion 

 as our knowledge increases. But when the 

 museums of the Old World were founded, 

 these relations were not even suspected. The 

 collections of natural history, gathered at im- 



