91 



SUCCESSION. 



In tracing the -.historical development of the principle of 

 succession, a difficulty constantly arises because of an un- 

 avoidable tendency to interpret the statements of earlier 

 authors in the light of later knowledge. Previous to 1880, 

 relatively few observations of the operation of this principle 

 had been made, and these were more or less incidental, ex- 

 cept in the case of some writers upon forestry, who made 

 no endeavor to connect the process with phytogeography. 

 The first recorded mention of succession seems to nave been 

 that of Biberg (1749:78), who indicated in a very general way 

 the changes of vegetation on rocks from the initial lichens 

 to the ultimate forest. DeCandoIIe (1820:27), in discussing 

 the struggle for existence, spoke of the cultures of the dunes 

 of the "Landes", in which the rapidly growing Genista, 

 after having served as a "cover" for seedlings of Pinus, was 

 finally driven out by the latter. The first use of the term 

 succession was by Stecnstfup in studying the changes of the 

 forest vegetation of Zealand (fide Grisebach (1844:16). Berg 

 (J844) studied the successive modifications of the deciduous 

 forests of the Harz in connection with their gradual disap- 

 pearance ; before the pines. Humboldt (1850: JO) evidently 

 recognized the presence of succession in vegetation, though 

 he mentioned it but incidentally: "All sea coasts afford evi- 

 dence of the hundreds, or even thousands of years, which 

 must pass before the moving sand can yield a firm basis for 

 the roots of herbaceous plants in those hot and rainless 

 regions where neither Lecideae nor other lichens can grow. ' ' 

 "In northern regions, the absence of plants is compensated 

 for by the covering of Baeomyces roseus, Cenomyce rangiferin- 

 us, Lecidea muscorum, Lecidea icmadophila, and other crypto- 

 gamia which are spread over the earth and which may be 

 said to prepare the way for the growth of grasses and other 

 herbaceous plants. In the tropical world, where mosses and 

 lichens are only observed to abound in shady places, some 

 few oily plants supply the place of the lowly lichen "(125). 



