170 HABIT AND INTELLIGENCE. [chap. 



habits motor, and mental characteristics of every living species 

 stractare'^ and individual be due to peculiarities of structure so 

 minute and subtle as to elude the microscope ? ^ 



I reply, that this would be a most plausible view if 

 habitual characters were confined to the individuals in 

 which they are formed. But this is not the case : all 

 habits (that is to say, according to my definition of the 

 word habit, all characters whatever) become, or tend to 

 become, hereditary. This is as certain as any proposition 

 can be which cannot be proved by experiment, but rests 

 contra- for its proof on cumulative evidence. Now, we have seen 

 embrv-^^ that an embryo consists, not of a miniature of the parent 

 ology. form, but of a small mass of germinal matter, without 

 structure or form, but having an inherited tendency to re- 

 produce the structure, form, and all the habitual characters 

 of its parents. This truth can be expressed in the lan- 

 guage of the theory of habit only by saying that every 

 habitual tendency passes, or tends to pass, from the organ 

 which is its seat (as, for instance, the brain is the seat of 

 mental habits) into the germinal matter of the body : and 

 Habits when a portion of that germinal matter is thrown off in 

 hereditary order to produce a new individual, it imparts its habitual 

 tendencies to the new individual. It is, no doubt, con- 

 ceivable that if oivc microscopes were powerful enough, 

 they might reveal some peculiarity of structure corre- 

 sponding to every habitual character of the fully formed 

 organism. But it is not conceivable that the microscope 

 should reveal peculiarities of structure corresponding to 

 peculiarities of habitual tendency in the embryo, which at 

 Habit is its first formation has no structure whatever. I therefore 

 myste- conclude that in all habitual tendency there is something; 



nous. •' * 



quite inscrutable and mysterious : as there certainly is 

 in the tendency of the germinal matter of the embryo to 

 develop into a new individual of its own species ; which, 

 indeed, is only a particular case of habitual tendency. 



^ This view of mental habits as dependiug on acquired peculiarities 

 of nervous structure, has been lately maintained, most ingeniously 

 and elaborately, by Professor Bain. (See the Fortnightly Review, 1st 

 February, 1866.) 



