BIOLOGICAL INVESTIGATIONS. 155 



only a form of habit a proposition which, with some restric- 

 tions, is true." l 



Repetition, or the reproduction of parallelisms, is equally 

 characteristic of memory and of heredity, nor can either be 

 conceived of as having a tendency to produce variations. It is 

 entirely reasonable that any novel acquired habit, due to con- 

 scious effort or to involuntary reactions of organisms in the 

 presence of external stimuli, may be regarded as one of the 

 products of memory. It follows from this that any structural 

 modifications which may result from the repetition of the same 

 acts or habits can, with equal reason, be attributed to memory. 

 The tendency of descendants to perform the same action, i.e., 

 to manifest the same habit in the presence of similar stimuli, 

 when no special structure has been originated, can thus be 

 readily accounted for if one considers heredity to be one form 

 of organic memory, or mnemism. 



When special tendencies or structures have arisen, their 

 reappearance in descendants at the same time, or earlier, does 

 not present the same difficulties that it seems to place in the 

 path of other theories, but becomes one of the strongest 

 confirmations of the mnemogenic hypothesis. 



In mnemonics it is the machine-like regularity of the succes- 

 sion of cause and effect, of one word begetting the next, that 

 surprises the student, the recurrence in the mind of long- 

 forgotten words, languages, and scenes, either through the 

 recurrence of some inciting cause or upon the removal of inter- 

 fering causes, as in the recapitulation of youthful reminiscences 

 in aged persons. Mnemotechnics, as embodied in the various 

 systems which have been devised to cultivate the memory, con- 

 sists essentially in teaching the habit of forming a chain of 

 associated ideas or words leading up to the word or thought to 

 be recalled. 



Even reversions that may be supposed to be purely sporadic 

 do not oppose any serious obstacle, since there must always be 

 latent mnemism in the cells and organs ready to manifest itself 

 whenever more recently acquired characters are prevented from 

 being developed in their proper succession. This is the most 



1 Heredity. Translation. New York, 1876. 



