HEREDITY. 451 



to be insuperable. Hyatt well expresses these in the 

 following language : ' ' Every purely corpuscular throng 

 . . . must not only account for a difficulty as great as 

 that of the camel and the needle's eye, but must also 

 account for putting the numberless characters derived 

 from the entire caravan of its immediate progenitors 

 and remote wild ancestors and their progenitors back 

 to the origin of their phylum, through the same nar- 

 row tunnel. This physical difficulty is still further 

 enhanced by the fact that the ova and spermatozoa do 

 not increase in size in proportion to the increasing 

 number of characters transmitted." {Froc. Boston Soc. 

 N. H., 1893, p. 70.) 



The transmission of a mode of motion organized in 

 a central nervous system, is less inconceivable. This 

 central system is the seat of a composition of incoming 

 stimuli and of outgoing energies, the resultant of both 

 combined constituting the active agency in the pro- 

 duction of automatic adaptive or intelligent adaptive 

 movements of any and all of the organs. It appears 

 to me that we can more readily conceive of the trans- 

 mission of a resultant form of energy of this kind to 

 the germ-plasma than of material particles or gem- 

 mules. Such a theory is sustained by the known cases 

 of the influence of maternal impressions on the grow- 

 ing foetus. Going into greater detail, we may compare 

 the building of the embryo to the unfolding of a record ^ 

 or memory, which is stored in the central nervous or- 

 ganism of the parent, and impressed in greater or less \ 

 part on the germ-plasma during its construction, in the 

 order in which it was stored. This record may be 

 supposed to be woven into the texture of every organic 

 cell, and to be destroyed by specialization in modified 

 cells in proportion as they are incapable of repro- 





