348 PROGRESS OF SCIENCE IN THE CENTURY. 



saurians and cuttlefishes, or to constitutional defects, 

 such as Lucretius thought of when he pictured races 

 going down to destruction " hampered all in their 

 own death-bringing shackles," or to other more or 

 less plausible reasons, but the suggestions remain very 

 vague and unsatisfactory. 



Against the puzzling facts of extinction, we have 

 to place the grander fact that, in spite of all, life 

 has been slowly creeping upwards. We may quote 

 a paragraph freely translated from Gaudry's En- 

 cJiainements du Monde animal dans les temps geo- 

 logiques (1878-1896). 



"The organic world taken as a whole has made 

 progress. Suppose a voyager on the oceans of ages; in 

 the Cambrian times his barque meets trilobites, but no 

 fishes; he nears the shore and there is the silence of 

 death. After long voyaging he finds himself at the end 

 of the primary era, fishes have replaced trilobites, and 

 on land there is no longer silence: there is the tramp 

 and cry of reptiles who prophesy the advent of warm- 

 blooded vertebrates. The traveller sails from age to 

 age and reaches the middle of the secondary era. 

 Charmingly beautiful ammonites play around his 

 vessel, legions of belemnites mingle with them; ichthy- 

 osaurs, plesiosaurs, and teleosaurs follow his track. He 

 goes ashore, and the giant dinosaurs resting on their 

 tails open their huge arms; pterodactyls and other 

 dragons swoop aloft; the first bird tries its wings, and 

 some small mammals show face timidly. Nature, mar- 

 vellous in the primary ages, has become yet more mar- 

 vellous; it has made progress. If our traveller be not 

 fatigued with his long wanderings, he will find in the 

 Tertiary ages the first monkeys, and horses, and a thou- 

 sand other mammals. Later on he will find himself 

 the man artist and poet minister and interpreter of 



