REGULATORY PROCESSES IN ORGANISMS 201 
constitution. Such a classification must also be available for both 
the so-called functional and form regulations, since every regula- 
tion probably involves both to some extent. 
Driesch’s classification of the regulations (Driesch, ’01, p. 95 
el seq.) is based upon a conception of regulation so widely differ- 
_ ent from the one developed in this paper that it does not assist us 
in distinguishing the processes involved.. From Driesch’s point 
of view, the physico-chemical processes in regulation are to a 
large extent of secondary importance and therefore cannot serve 
as a basis for classification. 
At present, however, we are practically unable to attain the 
proper basis for classification, since our knowledge of the processes 
involved is incomplete. Nevertheless we can distinguish with 
more or less certainty the resemblances and differences between 
different equilibria, and the following suggestions are based upon 
the character of the equilibria. 
We may distinguish two chief type of regulatory processes, 
first, quantitative equilibrations or compensations, and second, 
qualitative changes in equilibrium ortransformations. In compen- 
sation the rate or intensity of the processes, their continuation in 
time or their extension in space are concerned: in the transforma- 
tions their character as energetic processes, 7. e., the nature of the 
chemical reactions:and the physical changes. In the compensation 
the system remains much like that previously existing, as regards 
its character and the processes of equilibration are quantitative. 
In the transformations a new system, qualitatively different 
from that previously existing, arises as the result of equilibration. 
Most regulations, as they occur in nature aad experiment, involve 
both compensations and transformation in various degrees. This 
is especially true of the regulatory processes which follow the 
removal of a part. Here some parts of the organism undergo trans- 
formation in consequence of altered correlation, while compensa- 
tory processes of various kinds are evident, both in the increase 
in size of the new part and often also in a decrease in old parts. 
Moreover our use of these terms will depend upon the particular 
processes to which we have reference in a given case. The process 
of compensatory growth, for example, is highly complex in charac- 
