CHAPTER XIV 

 PALEONTOLOGY 



This much then we have gained, that we may assert without, 

 hesitation, that all the more j^erfect organic natures, such as fishes, 

 amphibious animals, birds, mammals, and man at the head of the list 

 were all formed upon one original type which varies only more or less 

 in parts which are none the less permanent, and which still daily 

 changes and modifies its form by propagation. — Goethe (1796). 



In a suggestive sentence, Haeckel speaks of our knowledge 

 of the line of descent in the history of any group of animals or 

 plants as being derived from "three ancestral documents — 

 morphology, embryology, and paleontology/' 



Of these three, paleontology is at once the most certain and 

 the most incomplete. Each fossil animal is a record, absolutely 

 authentic, so far as it goes, admitting of no doubt or question, 

 but for the most part yielding only a very little of the truth 

 involved in its existence. 



For no animal whatever is preserved as a fossil except as 

 the result of an unusual combination of circumstances. Only 

 those parts which are themselves hard, calcareous, silicious, or 

 horny, with rare exceptions, can retain their form in the rocks, 

 and even these, shells, teeth, bones, and the like, are often 

 crushed or distorted so that their actual form or nature may 

 be open to question. In addition, only the minutest fraction 

 of the sedimentary rocks of the earth has been laid bare by 

 artificial excavation or by natural erosion, and thus opened 

 to the inspection of man, and the number of fossils actually 

 observed can be only the most trivial fraction of i\ fraction of 

 the organisms actually existing and preserved. 



With all this, the hunian race has in the past shown a 

 singular lack 9t insight in the interprotfition of animal remains 



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