52 BIOLOGICAL LECTURES. 



initial structure of which determines all of its subsequent trans- 

 formations. The present theory also denies that there is or 

 can be anything passive in the germ that enters into its com- 

 position. 



A dynamical hypothesis of inheritance is correlated with all 

 the facts of physiology. It is in harmony with the dynamical 

 theory of sex, that sees only in sexuality the means developed 

 by another dynamical process (natural selection) that increases 

 the powers of a compound germ to survive and vary. It is 

 consistent with the facts of morphological super-position, with 

 the dynamical theory of the limit of growth, and duration of 

 life of organic species. It is also consistent with the view that 

 the initial or potential states of the germs of species are those 

 that must result whenever they are relieved from physiological 

 service to the parent organism. The apparent continuity of 

 germ plasm is, in many cases, only an effect of the equilibra- 

 tion of the forces of the organism, and has no further signifi- 

 cance. It must also deny any assumed isotropy of the germ 

 as inconsistent with fact. It assumes that the aeolotropy of 

 the molecular structure of the germ is followed by a gradually 

 increasing simplification of molecular structure of organs as 

 these are built up. Metabolism is assumed to be the sole 

 agent in effecting the mechanical and dynamical rearrange- 

 ment or sorting of the molecules into organs during develop- 

 ment. Specially endowed corpuscles or " biophors " are not 

 only needless as conditioning form or function, but also out of 

 the question, dynamically considered. No creature can be 

 supposed to have its life or germinal properties associated only 

 with certain corpuscles within it, since we cannot suppose an 

 organized whole dominated by a portion of it ; it is not possible, 

 for example, to conceive of individual life except from the 

 entire organism that manifests it. There can be no " biophors" 

 — bearers of life — the whole organism must do that as an 

 indivisible unit. Corpuscular doctrines of inheritance are 

 merely a survival in philosophical hypothesis of a pre-Aristo- 

 telian dens ex mac/nna. The dynamical hypothesis rejects the 

 deus ex macJmia, but finds a real mechanism in the germ that 

 is an automaton, but that is such only in virtue of its structure 



