COA'TEiVl'S. XI 



tions of environment in relation to time estimates — Relative order of 

 deposits in relation to depression and elevation, 73. — Order of deposits 

 with a sinking land — Order of deposits with elevation of land, 74. — 

 Characteristic fossils, 75. — Summary, 76. 



CHAPTER V. 



FOSSILS— THEIR NATURE AND INTERPRETATION, AND THE GEOLOGI- 

 CAL RANGE OF ORGANISMS. 



Fossils of vegetable and animal origin — Original material of fossils, 78. — 

 Various aspects of the original form represented — Preservation of fos- 

 sils, 79. — The majority of fossils are of marine organisms — Various 

 kinds of fossils enumerated. So. — Fossils represent chiefly the hard 

 parts of organisms — Best and most perfectly adjusted organisms of 

 the time left their records — General laws regarding the occurrence of 

 fossils. Si. — Change of the forms with passage of time, and particu- 

 lar forms characteristic of particular periods of time, undeniable facts 

 of Paleontology — Inorganic things, on the contrary, unchangeable — 

 Fossils characteristic of particular periods of geologic time, 83. — Stony 

 corals, the Zoantharia — Numbers of genera of the Zoantharia recorded 

 for each era, 84. — Two types of the Zoantharia indicated by the two 

 maxima of genera in separate eras in the time-scale — Table of the 

 number of genera of Madreporaria making their first appearance in 

 each geological system, grouped in families — Evolution curve of a 

 group of organisms, 85. — Evolution curves of the various types of the 

 Madreporaria, expressing the rate of generic differentiation of each 

 type — Meaning of these evolution curves, 87. — Chronological value of 

 family groups of genera — The life-period of a genus, 88. — Organisms 

 express evolution in their geological history; a fundamental law — The 

 meaning of genus and species, Sg. — The fossil coral, Favosites niaga- 

 rensis, as an illustration, 90. — Geological range and taxonomic ranks 

 of the characters, 92. — Table expressing the geological range of the 

 characters of the fossil Favosites niagarensis Hall, arranged according 

 to their taxonomic rank — Time-values of the characters of an individ- 

 ual differ according to their taxonomic rank, 93. — Stages of growth in 

 Ontogenesis, 94. — No successive stages of functional activity seen in 

 Phylogenesis — Contrast between the developmental stages of the in- 

 dividual and the succession of species, 95. — Evolution an organic pro- 

 cess, and not applicable to inorganic things — Fossils furnish the direct 

 evidence of evolution, 96. — Living organisms furnish direct evidence 

 of purposeful development, 97. — Fossils and geological biology — Hard 

 parts express both relation to environment and relation to ancestry, 

 98. — Kinds of hard parts of the animal kingdom preserved as fossils — 

 Protozoa, 99. — Ccelenterata, 100. — Echinodermata — Vermes — Arthrop- 

 oda, loi — MoUuscoidea, 104. — Mollusca, 105. — Vertebrata, 106. — 

 Summary, 109. 



CHAPTER VI. 



GEOGRAPHICAL DISTRIBUTION— THE GENERAL RELATION OE ORGANIS.US 

 TO THE CONDITIONS OF ENVIRONMENT. 



The importance of the study of geographical distribution, 112. — The nat- 

 ural conditions of environment : nomenclature — Natural-history prov- 



