CHAPTER XXV. RECOGNITION OF THE CHARACTER OF SOILS FROM THEIR NATIVE VEGETATION. UNITED STATES AT LARGE, EUROPE, 511.—Forest Growths outside of Mississippi; Alabama, Louisiana, Western Tennessee, and Western Kentucky, 511.—North Central States East of the Mississippi River, 513.—Upland and Lowland Vegetation in the Arid and Humid Region, 515.—Forms of Deciduous Trees in the Arid Region, 516.—Tall Growth of Conifers, 517.—Herbaceous Plants as Soil Indicators, 517.—Leguminous Plants Usually Indicate Rich or Calcareous Lands, 518.—European Observations and Views on Plant Distribution and its Controlling Causes, 519.—Composition of Pine Ashes on Calcareous and Non-calcareous Lands. Table, 520.—Calciphile, Calcifuge, and Indifferent Plants, 521.—Silicophile _vs._ Calciphile Flora, 523.—What is a Calcareous Soil? 524.—Predominance of Calcareous Formations in Europe, 525. CHAPTER XXVI. THE VEGETATION OF SALINE AND ALKALI LANDS, 527.—_Marine Saline Lands_, 527.—General Character of Saline Vegetation, 527.—Structural and Functional Differences Caused by Saline Solutions, 528.—Absorption of the Salts. Table, 529.—Injury from the Various Salts, 531.—Reclamation of Marine Saline Lands for Culture, 533.—_The Vegetation of Alkali Lands_, 534.—_Reclaimable_ and _Irreclaimable Alkali Lands_ as Distinguished by their Natural Vegetation, 534.—Plants Indicating Irreclaimable Lands, 535.—Tussock Grass; Bushy Samphire; Dwarf Samphire; Saltwort; Greasewood; Alkali Heath; Cressa; Salt Grass, 536.—Relative Tolerances of the different Species; Table, 549. APPENDICES. A.—Directions for taking Soil Samples, issued by the California Experiment Station, 553. B.—Summary Directions for Soil-Examination in the Field or Farm, 556. C.—Short Approximate Methods of Chemical Soil-Examination Used at the California Experiment Station, 560. General Index, 565. Index of Authors referred to, 591. PREFACE. This volume was originally designed to serve as a text and reference book for the students attending the writer’s course on soils, given annually at the University of California, who complained of their inability to find in any connected treatise a large portion of the subject matter brought before them. As all these students had preliminary training in physics, chemistry and botany, no introductory chapters on these general subjects were necessary or contemplated; the more so as good elementary treatises embracing the needful preparation are now numerous.