DIRECTIONS FOR COLLECTING AND PREPARING FOSSILS. 



By Charles Schuchert, 

 Assistant Curator of the Department of Paleontology, 



- INTRODUCTION. 



The object of this treatise is to instruct beginners in the study of 

 paleontology in regard to the best methods of collecting and preserving 

 fossils. It should be borne in mind, however, that there are no laws 

 governing the formation of a collection of fossils. Each individual 

 will have his own way o± working out details, and all that is here 

 attempted is to lay before the reader some methods which in the expe- 

 rience of many have proved most advantageous. 



PAET I. — FOSSILS AND THEIR MANNER OF OCCURRENCE. 



DEFINITIONS. 



According to a definition proposed by Charles Lyell, a fossil is "any 

 body, or the traces of the existence of any body, whether animal or 

 vegetable, which has been buried in the earth by natural causes." 



Fossils, or "petrifactions," as they are sometimes termed, may also 

 be defined as parts of plants and animals once living in the water, on 

 the land, or in the air. Fossils are never more than parts of organ- 

 isms, since the soft structure of the later can not be preserved, though 

 impressions or casts of them are sometimes retained in fine sediments 

 or muds. It follows, therefore, that fossils are usually the relics of the 

 hard parts of organisms, such as the shells of mollusks, the skeletons 

 of sponges and corals, the bones of fishes, birds, or mammals, and the 

 wood, bark, or leaves of plants. These ancient organisms were buried 

 by the accumulating sediments of oceans, lakes, or marshes. Fossils 

 may preserve much of their original mineral matter, or may have it 

 greatly altered or entirely replaced, subsequent to their burial, by 

 other mineral substances. Footprints, trails, or burrows left by ani- 

 mals upon sand or mud are also included under the term fossils, though 

 these objects were at no time x)arts of animals. 

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