REGULATORY PROCESSES IN ORGANISMS 211 
from each other,so may the results of reconstitution, even in differ- 
ent pieces of the same individual, differ from each other. More- 
over, as a certain amount of water does not, except under certain 
conditions, form a river, so does a piece of an organism reconstitute 
itself to a whole only under certain conditions. 
2. The initiating factor in reconstitution 
As Driesch has pointed out (Driesch, ’01), it is evident that 
reconstitution occurs as the result of the absence (‘Nichtmehr- 
vorhandensein’) of something. What is this something? Is it 
the structure, the form, or is it activity? In plants it is possible 
to bring about reconstitution, 7. e., the formation of new buds, roots, 
etc., by inhibiting the metabolic activity of the existing growing 
regions without their removal, e. g., by enclosing them in plaster or 
in an atmosphere of hydrogen, or even by applying anesthetics 
locally between them and the regions concerned. In another 
paper I have considered numerous cases of this sort and have dis- 
cussed their significance at length (Child, ’1la). These facts show 
very clearly that it is not the form or structure which is involved 
but a process, an activity, whose effect is transmitted insome way 
from one part to another. If we stop the metabolism of the one 
part for a time the effect on the other is the same as if the first 
part had been removed. These facts alone should be sufficient to 
prevent us from regarding form regulation as a process distinct 
from functional regulation. It is the absence of the effect of cer- 
tain processes in a certain part or in certain parts, which initiates 
reconstitution. In short, it is the absence or decrease below a cer- 
tain point of certain physiological correlative factors which were 
previously present, that initiates reconstitution. In the absence 
or decreased effectiveness of these correlative factors, the remain- 
ing parts, still being subjected to other correlative factors, which 
may themselves gradually change in consequence of the removal 
or decreased activity of the part, react ina manner different from 
their previous reactions, simply because they are under different 
physiological conditions. Reconstitution is then initiated by a 
change in physiological correlation. Recently Driesch (’09) has 
