298 EVOLUTION AND ANIMAL LIFE 



to the great class of animals predominating at that time. Of 

 course, in each of the later epochs there lived animals represent- 

 ing the principal classes or groups in all of the preceding ones, 

 as well as the animals of that particular group which may 

 have first appeared in this epoch, or was its dominant group, 



Fig. 177. — Restoration of Dimorphodon macronyx, showing probable wings. 



(After Seeley.) 



In the study of fossils not only is it necessary for us to 

 consider the actual forms and structures and the species they 

 represent, but we should so far as possible reconstruct the con- 

 ditions under which the organisms were alive, and the threads 

 of genealogy which connect those of one period with those 

 which precede or follow them. By such studies as these we are 

 brought close to a consideration of the method of creation, and 

 to a knowledge not only of the origin of species but to the 

 causes underlying the divergence of the great trunks of animal 

 and plant life. 



"In youth," says Dr. A. S. Packard, "the older naturalists of the 

 present generation were taught the doctrine of creation by sudden, 

 cataclysmal, mechanical creative acts, and those to whose lot it fell 

 to come into contact with the ultimate facts and principles of the new 

 biology had to unlearn this view, and gradually to work out a larger, 

 more profound, wider reaching and more j^hilosophic conception of 

 creation." 



An early paleontologist, Dr. A. Gaudry, utters these sug- 

 gestive words: 



"We cannot refrain from looking with curious admiration upon 

 the innumerable creatures that have become preserved to us from 



