132 Oermany. 



In zoology the early writers began with a description 

 of the biology of game animals, ISTert, interest in forest 

 insects became natural and in 1818 Bechstein in his En- 

 cyclopsedia devoted one volume (by Scharferiberg) to the 

 natural history of obnoxious forest insects. Toward the 

 middle of the century with the cultivation of forests and 

 especially the planting of large areas with single species, 

 insect pests increased, hence the interest in the life 

 histories of the pests grew and gave rise to the cele- 

 brated work by Eatzehurg, "Die Waldverderher und 

 Ihre Feinde" (1841). A number of similar hand-books 

 on insects and on other zoological subjects followed ; the 

 last, a most complete work on insects, being still based 

 on Eatzeburg's work is that of Judeich and Nitzsche, in 

 two volumes (1895). Of course, the general works on 

 forest protection always included chapters on forest 

 entomology. The first of these text-books on forest pro- 

 tection was published by Laurop (1811), and others by 

 Bechstein, Pfeil, Kauschinger and recently by Hess 

 (1896), and FiXrst (1889). 



Knowledge of the soil was but poorly developed in 

 the encyclopedic works of the earlier part of the period. 



Not till Liebig's epochmaking investigations was a 

 scientific basis secured for the subject. Then became 

 possible the improvements in the contents of such works 

 as Grebe (1886), Senft (1888), and of Gustav Heyer, 

 whose volume {Lehrbuch der Forstlichen BodenJcunde 

 und Klimatologie, 1856), well records the state of 

 knowledge at that time. But only since then has this 

 field been worked with more scientific thoroughness by 

 Ebermayer, Schroeder, Weber, Wollny and by Ramann, 



