276 Theories Treating of Inheritance 
stance, similar throughout the whole organism, which 
as he himself states, makes histological differentiation at 
least inexplicable. 
THEORIES OF CHEMICAL DEVELOPMENT 
In his fundamental work “The Struggle of the Parts 
of the Organism,” and therefore at a time, before Roux 
had yet reached the preformistic view of idioplasm or 
germ plasm which he later very clearly adopted, and 
which in many respects is like the conception of Weis- 
mann; when also he still considered development to be 
rather the complex result of a long series of purely 
chemical phenomena, and nevertheless had not yet wel- 
comed Weismann’s theory of the non-inheritance of 
acquired characters as a deliverance from a nightmare, 
at that time he sought to explain this inheritance in the 
following way: 
First he notes that the germ plasm although it be- 
comes separated at the very commencement of develop- 
ment from the organism in process of formation, 
“remains nevertheless dependent upon and in relation 
with this organism; for it must be fed and grow and 
multiply and to that end it receives its nourishment from 
its parent by chemical metabolism, and might still be 
influenced in its own nature in this way.” ?°° 
He supposes further that on the one hand each 
structural formation may be conditioned by certain spe- 
cial, chemical relations, and vice versa that each variation 
of form which the adult organism undergoes through 
functional adaptation produces in its turn a certain 
*°°Roux: Der Kampf der Teile im Organismus. P. 60. 
