AUTHOR'S PREFACE vii 



oecological problems, and are framing their theoretical opinions 

 on the basis of accurately observed facts and critically conducted 

 experiments. 



A satisfactory general survey of oecological plant-distribution 

 cannot be attempted with the material at present available. This 

 book is therefore chiefly of a tentative nature, and attempts by 

 a precise statement of pending questions to stimulate further 

 research. 



The Greatest care has been given to the choice and execution 

 of the illustrations, which, by the delineation partly of single 

 objects and partly of masses of vegetation, portray the connexion 

 between plant-life and its environment much better than the most 

 detailed descriptions. Thanks to the great kindness of a number 

 of fellow botanists and naturalists, I have been able to collect 

 a number of photographic views of characteristic vegetation. I 

 am indebted to the following gentlemen and departments, to whom 

 I now again express my gratitude : — forest-inspector W. W. Ashe 

 (N. Carolina), Privatdoc. A. Bauer (Marburg), Prof. Bessey (Lin- 

 coln, Nebr.), Sir Dietrich Branclis (Bonn), Prof. D. H. Campbell 

 (California), L. Cockayne (Christchurch, New Zealand), Prof. J. M. 

 Coulter (Chicago), Prof. Deichmiiller (Bonn), the Geological depart- 

 ment of the University of Nebraska, Grigoriew, Secretary of the 

 Imp. Russian Geographical Society (St. Petersburg), P. Groom (Ox- 

 ford), Prof. G. Karsten (Kiel), Lieutenant Kaznakoff (St. Petersburg), 

 J. Kobus (Pasoeroean, Java), Prof. Krasnov (Kharkov), Dr. P. Kuc- 

 kuck (Heligoland), G. Ktippers-Loosen (Cologne), Prof. Kukenthal 

 (Jena), Prof. Kusnezov (Dorpat), Prof. MacMillan (Minneapolis), 

 Prof. Pohlig (Bonn), Prof. Rothrock (West Chester, Pa.), Prof. Sar- 

 gent (Brooklyn, Mass.), Privatdoc. A. Schenck (Halle), Prof. H. 

 Schenck (Darmstadt), F. Sonnecken (Bonn), Dr. O. Stapf (Kew), 

 Geheimrath Prof. Strasburger (Bonn), W. Swingle (Florida), Dr. 

 Treub (Buitenzorg, Java), Prof. O. Warburg (Berlin), G. H. Webber 

 (Florida). Lady Brandis of Bonn has also been kind enough to 

 place at my disposal her beautiful Indian water-colour drawings, 

 which are so true to nature. 



I have also to thank several of the above-mentioned gentle- 

 men for important assistance in reference to literature, research- 

 material, and the like. In this respect I am indebted also to the 



