96 Germany. 
bued with the necessity of basing forest management on 
exact scientific inquiry, instead of on empiricism alone, 
he formulated instructions for forest static investiga- 
tions, a subject which his son, Gustav Heyer, elaborated 
into a science. 
4. Progress in Silviculture. 
a. Natural regeneration continued to be the favorite 
method well into this period, and for a long time selec- 
tion forest and coppice were all that was known in prac- 
tice until Hartig and Cotta forced recognition of the 
shelterwood system. 
The only way in which a transition from the generally 
practiced, unregulated selection forest to an intensive 
Management was possible, with the ignorant personnel 
of underforesters, was to formulate into an easily intelli- 
gible prescription the necessary rules, allowing the least 
play to individual judgment. This was done by Hartig 
when he formulated his eight “General Rules” (1808) 
which coincided also closely with the teachings of Cotta. 
Since these rules represent in brief and most definitely 
the status of silvicultural knowledge on natural regen- 
eration at the time, it may be desirable to translate them 
verbatim. 
(1) “Every forest tree which is expected to propagate 
itself by natural regeneration must be old enough to 
bear good seed. 
(2) “Every district or stand which is to be replaced 
by a thoroughly perfect stand by means of natural re- 
generation, must be brought into such position (density) 
that the soil may everywhere receive sufficient seeding. 
(3) “Each compartment must be kept in such condi- 
