The Plant- Geography of Gen 



THE PLANT-GEOGRAPHY OF GERMANY. 



By Roscoe Pound. 



a recently published address Dr. Coulter speaks of a new 

 l botany which is sending botanists " to the great 

 laboratory of nature," and replacing collecting trips by biolog- 

 ical surveys. "The old-fashioned collection of plants/' he 

 says, "will hold no more relation to the new field work than 

 the old geology, with its scattered collection of fossils, holds to 

 the topographic geology of to-day." Geographical botany as 

 it is now understood is comparatively a recent development. 

 Collectors and cataloguers for a long time have been gathering 

 a portion of the bare facts upon which geographical botany 

 must proceed, and the facts of plant-distribution have been 

 more or less ascertained. But the systematic collating and 

 grouping of these facts and the application of biological and 

 physiological facts to them is a matter of the last few years 

 and is still going on. At first localities were catalogued, and 

 collectors were eager to add new and rare stations to those 

 recorded for species; then came statistical comparison of 

 families and genera, especially in relation to altitude and the 

 media of plant-migration. The limits of distribution of species 

 were ascertained, particularly of those which are characteristic 

 and controlling in vegetation. Such work laid the foundations 

 of geographical botany. 



But the statistics as to the distribution of families, which 

 have been worked out in one method and another, gave no 

 promise of leading to important results. It was not until 

 biological groups began to be made for the purpose of com- 

 parison, and statistics began to be applied to those groups, that 

 such work acquired importance. It is apparent that a mere 

 statement of the number of species of the various natural plant- 

 groups occurring in a certain region tells us very little of the 

 vegetation of that region except in the most general way. A 

 group represented by comparatively few species may yet as far 

 as the occupation of the soil is concerned be dominant and 



