BIOLOGICAL INVESTIGATIONS. I 53 



decision that this substance is not a peculiar plasm but a dif- 

 ferentiated product of each organism undergoing a process of 

 rejuvenation as each link in the chain of being is forged, seems 

 more in accord with the facts than that which demands a wave- 

 less linear transmission of some peculiar substance. 



Neither of these theories excludes the conclusion that heredity 

 of the transmission of like by like is a function of the automatic 

 repetition of the same act, or, in other words, identical with 

 what we call unconscious memory ; but it is obvious that if 

 heredity can be expressed by the term " mnemism," the greatest 

 difficulties are removed from the path of the theory of pan- 

 plasm. This last cannot provide of itself any reasonable 

 explanation of the successive stages of development and their 

 recapitulations of ancestral characters, but with the aid of 

 mnemogenesis it can fully explain these phenomena. 



Professor Cope has insisted upon the truth of this theory in 

 two essays. The following are quotations from his article 

 " On Inheritance in Evolution": 



If the doctrine of kinetogenesis be true, this energy (the build- 

 ing energy) has been moulded by the interaction of the living being 

 and its environment. It is the expression of the habitual movements 

 of the organism which have become impressed on the reproductive 

 elements. It is evident that these and the other organic units of 

 which the organization is composed possess a memory which deter- 

 mines their destiny in the building of the embryo. This is indicated 

 by the recapitulation of the phylogenetic history of its ancestors dis- 

 played in embryonic growth. This memory, perhaps, has the same 

 molecular basis as the conscious memory ; but, for reasons unknown 

 to us, consciousness does not preside over its activities. The energy 

 which follows its guidance has become automatic, and it builds what 

 it builds with the same regardlessness of immediate surroundings as 

 that which is displayed by the crystallific growth energy. It is inca- 

 pable of a new design. It appears to me that we can more readily 

 conceive of the transmission of a resultant form of energy of this 

 kind to the germ plasma than of material particles of gemmules. 

 Such a theory is sustained by known cases of the influence of mater- 

 nal impression upon the growing foetus. Going into greater detail, 

 we may compare the building of the embryo to the unfolding of the 

 record of a memory which is stored in the central nervous organism 



