57 



foundation for our vertebrate palaeontology. The energy of 

 Cope has brought to notice many strange forms, and greatly 

 enlarged our literature. Agassiz, Owen, Wyman, Baird, 

 Hitchcock, Deane, Emmons, Lea, Allen, Gibbes, Jefferson, 

 DeKay, and Harlan, deserve honorable mention in the history 

 of this branch of science. The South American extinct verte- 

 brates have been described by Lund, Owen, Burmeister, Ger- 

 vais, Huxley, Flower, Desmarest, Aymard, Pictet, and Nodot. 

 Darwin and Wallace have likewise contributed valuable infor- 

 mation on this subject, as they have on nearly all forms of life. 



In this long history of ancient life I have said nothing of 

 what Life itself really is. And for the best of reasons, because 

 I know nothing. Here at present our ignorance is dense, and 

 yet we need not despair. Light, Heat, Electricity, and Magnet- 

 ism, Chemical Affinity and Motion, are now considered different 

 forms of .the same force; and the opinion is rapidly gaining 

 ground that Life, or vital force, is only another phase of the 

 same power. Possibly the great mystery of Life may thus be 

 solved, but whether it be or not, a true faith in Science knows 

 no limit to its search for Truth. 



LIBRARY 



CKJVEBSITT OF 



CALIFORNIA. 



