I NON-INHERITANCE OF INJURIES 13 



such injuries incurred only once and not repeated. It is true 

 there are injuries which, although they have been always 

 repeated constantly, are yet never inherited. Among these 

 is the rupture of the hymen in women. 



In such cases we must presume a specially effective power 

 of correlative activity,^ directed to the part affected and 

 residing in the whole organism — the same compensating 

 power which leads m lower animals during the life of the 

 individual to the regeneration of parts which have been lost 

 or artificially removed.^ But these cases do not prove the 

 general proposition that injuries are not inherited ; they do 

 not prove that even injuries which have been repeated during 

 a considerable period are not inherited. Hitherto little 

 importance has been attached to the demonstration of the 

 inheritance of injuries. Yet single cases of the inheritance 

 of injuries only once incurred seem to me to be thoroughly 

 authenticated. To these I shall refer subsequently. 



For the rest, it can I believe be proved as a fact that 

 acquired characters are inherited. 



The germ -plasm cannot possibly, in my view, remain un- 

 touched by the influences which are at work on the whole 

 organism during its life. Such an immunity would be a 

 physiological miracle, merely on account of the morphological 

 relations of the animal ovum and spermatozoon, and their 

 dependence on the nutritive processes of the body,^ — a miracle 



■'■ Correlation = the principle that the characters of the living being are so 

 connected with one another that one determines the other. 



2 The more imperfect the structure of animals, i.e. the lower their organisation, 

 the less degree to which division of labour is carried out, so much the greater the 

 facility with which injuries are repaired, so that many of the lower animals can 

 be even cut into pieces with the result that each piece grows again into a perfect 

 animal, just as in many plants. (Cf. on this i:)oint the Appendix : On the Idea 

 of the Animal Individual.) The inheritance of injuries is thus of but slight 

 importance in the discussion of heredity in general. 



2 1 have myself described arrangements of quite surprising character for the 

 nutrition of animal ova. Cf. my memoirs on the ova of Keptiles, Birds, and Fishes, 

 in Arch. f. mik. Anat. Bd. viii. 1872. 



