28 MARRIAGE AND DISEASE. 



It would perhaps be convenient to point out here 

 that all variations from the normal standard of deve- 

 lopment and health can be classed under two heads, 

 physiological and pathological : 



Physiological where the variation takes the form of 

 special development in any healthy direction, whether 

 physical, mental, or moral ; and 



Pathological where the variation tends downwards to 

 degeneration and disease, or to absence of due develop- 

 ment, as where insanity, idiocy, bodily deformity, gout, 

 scrofula, and like hereditary diseases and imperfections 

 brand the family stock that is, where the variation 

 tends toward dissolution. 



And now let us briefly consider the action of the 

 environment in the production of variations. The 

 influence of the environment is at work from the 

 instant of conception. The child's environment, made 

 up of pressure, food, air, exercise, education, associa- 

 tion the whole outer world, in fact, is with all Nature 

 ever changing; and as it is impossible that this ever 

 can be identical in any two cases, so it is impossible, 

 on this ground alone, that any two children ever can 

 be exactly alike. Thus each individual must be a 

 variation from the mean of his parents, as he must 

 also, and from the same cause, be a variation from 

 the normal. (The normal is of necessity ideal, as we 

 cannot point to any individual and say, "This is the 

 normal standard," for the reason that no one is, 

 perhaps, absolutely healthy, and every one has been, 

 and is being, modified by his environment.) But 



