98 



change, from the unaltered state of shells in modern mud- 

 flats to the crystalline condition of an ancient limestone 

 fossil, in which the original structure has been completely 

 lost. It is, then, obvious that palaeontologists should follow 

 geologists, and extend the term fossil to include all remains 

 of animals and plants preserved from the time of the earliest 

 fossiliferons strata to the present. As Geikie says: "The 

 idea of antiquity or relative date is not necessarily involved 

 in this conception of the term . . Thus, the bones of a sheep 

 buried under travel and silt bv a modern flood and the 

 obscure crystalline traces of a coral in ancient masses of 

 limestone are equally fossils."' * 



Geologic time is continuous, and the development of life is 

 progressive. No break divides the present from the past, 

 and the geologic phenomena of the present epoch are con- 

 trolled by the same laws which governed those of past time. 

 Fossilization is a mere accident bv which some animals 

 and plants are preserved, and it resolves itself into a process 

 of inhumation, neither the nature of the organism nor the 

 time or mode of burial being of primary significance. These 

 are of first importance in determining the degree of preserva- 

 tion which the fossil is to experience, and, consequently, the 

 nature of the record which is to remain; but thev do not 

 affect the process of fossilization, which is merely the buried 

 of the dead organism. Thus, the idea of change is not neces- 

 sarily involved in the concept of a fossil, although it is true 

 that few organisms long remain buried without undergoing 

 some chemical change. Examples of the preservation of 

 organisms in an almost unchanged condition are neverthe- 

 less known, the most conspicuous being the mammoths 

 frozen into the mud and ice of Siberia, and retaining hair, 

 skin, and flesh intact; and the insects and other animals 

 includedinthe amber of the Baltic, where thev have remained 

 unchanged since early Tertiary time. Ordinarily, however, 

 the flesh of the buried animal soon decays, and, consequently, 

 no record of the soft parts is retained. In plants, the decay 



* Text-book of Geology, 3d Ed., p. 645. 



