APPENDIX. 767 



as to life was involved in the progress in climate, etc. — 601. Genera ranging 

 through all time from the first Palaeozoic Epoch. — Cause of extinction of spe- 

 cies, and of tribes or higher groups. — 601. Teachings of Geology as to the origin- 

 ation of species. 



XXIII. Dynamical Geology. — Page 603. Subjects treated of under Dynami- 

 cal Geology. — 604. Life : its protective effects. — 605. Its transporting eft'ects. — 

 Its destructive effects. — 606. Conditions determining its importance in rock- 

 making. — Limiting influence of climate and soil. — Id. of the nature and purity 

 of the water. — 608. Id. of temperature and depth. — Kinds of organic products 

 from plants ; shells ; corals ; bones ; diatoms ; sponges. — 609. Reasons why 

 water-species have contributed most to rocks. — 611. The grade of species best 

 fitted for rock-making. — Methods of fossilization. — 612. The method of rock- 

 making in the case of minute fossils. — Id. in the case of corals and shells. — 613. 

 Formation of peat. — 614. Causes limiting the distribution of coral reefs and 

 islands. — 615. Description of a coral island. — 617-619. Formation of the coral 

 structure. — 620. Kinds of coral reefs. — 621. Extent and thickness. — 622. Origin 

 of the forms of reefs. — 624. Recapitulation. — 625. Cohesive Attraction : its 

 identity with the power of crystallization. — 626. Cleavage in minerals and in 

 rocks. — Cause of the concretionary structure; origin of the columnar forms of 

 trap. — 628. The Atmosphere: its destructive effects through the transportation 

 of sands. — 629. Its method of adding to lands. — Dunes. — Dust-showers. — 632. 

 Effects of changes in atmospheric pressure. 



XXIV. Water. — Source of the water of Rivers, and the conditions on which 

 the amount depends. — 634. Law of flow of a stream. — 635. Ratio of the force of 

 running water to the velocity. — General effects of erosion. — Progress of erosion 

 in forming valleys. — 636. Distinction of torrent-portion and river-portion ; flood- 

 plain. — 637. Modifications dependent on the nature of the rocks. — 641. Pot-holes. 

 — 642. Materials transported by rivers. — 643. Extent of denudation over a conti- 

 nent. — Wearing of stones. — Amount of silt annually carried to the Mexican 

 Gulf by the Mississippi. — 644. Raft of the Red River. — Origin of alluvial 

 formations, and their features. — 645. Origin of deltas. — 647. The manner in 

 which waters become subterranean. — 648. The principles on which Artesian wells 

 are based. — 649. Erosion. — The three kinds of land-slides. — 650. The Ocean : 

 means by which the ocean exerts mechanical force. — General system of currents ; 

 their universality, rate, and position. — 652. In what way their positions might 

 be changed. — Simpler tidal actions. — 653. Translation-character of waves on 

 coasts. — In-flowing currents. — Eagre. — Out-flowing currents. — -654. Waves, their 

 force. — Surface-currents caused by winds. — 655. Under-currents id. — Earth- 

 quake-waves. 



XXV. Water, Concluded. — Erosion by currents. — 656. Erosion by waves ; its 

 extent; height of line of greatest action above low-tide level. — 657. Amount 

 of transportation by oceanic currents, and the materials transported. — 658. 

 Transportation by waves. — 659. Formations over the bed of the ocean. — 660. 

 Formations on soundings and along coasts. — Action of tidal and wind currents 

 in determining the forms of accumulations. — 661. Results from the combination 

 with those of the currents of rivers. — 662. The consequent features of the eastern 

 coast of the United States. — 664. Beaches ; ripple-marks. — 665. Oblique lami- 

 nation ; rill-marks. — Erosion during the slow sinking or rising of a continent, 



