466 PROCEEDINGS OF THE ACADEMY OF [1892. 



" The preceding paragraph contains, in essence, my own hypoth- 

 esis according to which all the facts of hereditary transmission and 

 variation may be coordinated without losing or rendering unavailable 

 the advantages which may be derived from the supposition that 

 acquired characters may be transmitted. 



" In my view metabolism itself becomes the means of transmit- 

 ting the changes in the adult organism, due to the complex interac- 

 tion between it and its surroundings to the idle, functionless and 

 passive germ-cells, because it is a demonstrable fact that these are 

 the only cells in a multicellular organism which have no work to 

 perform which is of direct benefit to the individual life of that 

 organism, unless it may be to take up the surplus nutriment not 

 used by the metabolism of the parent-body in the secular exhibition 

 of the sum total of its physiological energies, in the struggle for 

 existence." 



According to my view the idioplasmic, or specific molecular 

 character of the plasma of the germ-cells, in common with that of 

 the protoplasm of the whole body (which latter always tends to 

 repair injuries, or even, in lower forms, replace lost parts,) tends, in 

 virtue of its dynamically acquired specific traits, to repeat the 

 organization of its parent type, in the course of its development, 

 not because it is something different from the protoplasm of the cells 

 of the rest of the body, but because it is wholly unspecialized and 

 without other physiological differentiation. 



The automatic processes of heredity are an accumulated result of 

 the continuous interaction of internally and externally developed 

 energies during phylogeny. The exact manner in which these have 

 been registered and preserved in germinal cells, or in parts of organ- 

 isms which have the power to reproduce the whole organism, we 

 cannot yet hope to explain, in that protoplasm itself is a body of 

 such complexity and capability of transformation, that nothing else 

 approaches it, as is proved by the chemistry of its bye-products, the 

 carbon compounds. 



We can only suggest that " molecular impressions experienced in 

 the course of variations in the modes of manifestation of, or disturb- 

 ances of the balance of the metabolism of the parent-body are sup- 

 posed upon this view to be transmitted as molecular tendencies to the 

 idle or passive plasma of the germ-cells. Variations in the molecu- 

 lar constitution and tendencies of the germinal matter are supposed 

 to thus arise at different times in the same parent, and that, conse- 



