568 PALEONTOLOGY 



graphy, when pursued in a purely biological spirit, let us employ an 

 imaginary problem. Figure to yourselves a continent absolutely un- 

 known in any of its physical features of earth, climate, or configura- 

 tion; let us imagine that from such an unknown continent all the ani- 

 mals and all the plants could be brought into a vast museum, the only 

 condition being that the latitude and longitude of each specimen 

 should be precisely recorded, and let us further imagine a vast num- 

 ber of investigators of the most thorough zoological and botanical 

 training, and with a due share of scientific imagination, set to work on 

 this collection. Such an army of investigators would soon begin to re- 

 store the geography of this unknown continent, its fresh, brackish, and 

 salt-water confines, its seas, rivers, and lakes, its snow peaks, its gla- 

 ciers, its forests, uplands, plains, meadows, and swamps; also even the 

 cosmic relations of this unknown continent, the amount and duration 

 of sunshine as well as something of the chemical constitution of the 

 atmosphere and of the rivers and seas. Such a restoration or series of 

 restorations would be possible only because of the wonderful fitness 

 or adaptation of plants and animals to their environment, for it is 

 not too much to say that they mirror their environment. 



At the historic period commemorated by this great exposition of 

 St. Louis, when Napoleon concluded to sell half a continent to 

 strengthen his armies, it is true that such a solution of a physical 

 problem by biological analysis might have been conceived by the pu- 

 pils of Buffon, by Napoleon's great contemporaries, Cuvier, Lamarck, 

 or Saint-Hilaire, but the solution itself would not have been possible. 

 It has been rendered possible only by the wonderful advance in the 

 understanding of the adaptation of the living to the lifeless forces of 

 the planet. Finally, it is obvious in such a projection of the physical 

 from the purely biological that the degree of accuracy reached will re- 

 present the present state of the science and the extent of its approach 

 toward the final goal of being an exact or complete science. The illus- 

 trative figure need not be changed when the words paleozoology 

 and paleobotany are substituted for zoology and botany. We still 

 read with equal clearness the physical or environmental changes of 

 past times in the biological mirror, a mirror often unburnished and 

 incomplete owing to the interruptions in the paleontological records, 

 but constantly becoming more polished as our knowledge of life and 

 its all-pervading relations to the non-life becomes more extensive and 

 more profound. 



Such an achievement as the reconstruction of a continent would be 

 impossible in paleontology pursued as geology or as a logical subdi- 

 vision of geology. The importance of the services which paleontology 

 may render geology as time-keeper of the rocks, or which geology 

 may render paleontology, are so familiar that we need not stop to 

 enumerate them. To emphasize the relation I have elsewhere sug- 



