3 



Darwin says we are obliged to admit that certain characters,, 

 aptitudes, and instincts may remain in the latent state in an 

 individual, while yet we are unable to find any trace of their 

 presence ; thus may the above resemblances be explained. 

 These latent characteristics of heredity are peculiarly 

 applicable to what may be termed "heredity occurring at 

 corresponding periods," which may be explained on the 

 hypothesis of latent characteristics contained in the 

 individual, in the germ state, and which come to light only 

 under definite conditions, at some particular point of his 

 development, and this particular moment corresponding with 

 a similar moment in the progenitor. 



Ribot thus graphically says: "Still it is evident that 

 these formulas cannot pretend to give a complete explanation 

 of a fact so abstruse and so complex as hereditary trans- 

 mission. Our only purpose is to show that the term is 

 taken in too narrow a sense when it is restricted to two 

 generations, and that the facts seem less strange so soon as 

 we grasp them as a whole. We desired also to exhibit 

 the wonderful tenacity of heredity. Its law is absolute 

 transmission ; and, in spite of all the obstacles which tend 

 to weaken or destroy it, it struggles on without truce or 

 pause, losing much of its strength as it advances, dissipating 

 itself, so to speak, so as to appear no longer to exist, and 

 yet, when we see the same characters reappear, sometimes 

 after a hundred generations, here is, indeed, matter for 

 reflection. It may be said that heredity verifies in its own 

 way the axiom Nothing is lost. With its character of 

 unconquerable firmness, of obstinate persistency, it appears 

 to us as one of those many inflexible bonds by which 

 omnipotent nature imprisons us in necessity." 



