CHAPTER X 

 ZOOLOGY OF FOSSIL REMAINS 



THERE is one large division of zoology not yet 

 touched upon the study of the remains of extinct 

 animals. This is obviously a department of zoology 

 although it is more frequently placed with geology 

 under the name of paleontology. The extinct 

 animals were ancestors of those now living and many 

 revelations are found by studying their fossil re- 

 mains. The fossil remains of animals are so nu- 

 merous and cover such a long range of time, that we 

 have preserved in the rocks not only a picture of the 

 succession of animal life on the globe for many cen- 

 turies, but, also, records of the transmutations or the 

 structural changes they have undergone. These open 

 such a wide sweep of observation that they are of 

 incalculable value in the study of zoology. 



It is estimated that if the fossil bearing rocks were 

 accumulated in one series they would measure more 

 than forty miles in thickness and represent a period 

 of several millions of years in their formation. Exam- 

 ination of the fossils from the lower rocks shows that 

 for many aeons there were no vertebrate animals, and, 



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