184 ACQUIRED CHARACTERS SEC. 



to me that in the preceding instances enough of the inherit- 

 ance of injuries has been given to prove this inheritance 

 putting aside my previous attempt to argue in favour of the 

 same conclusion from the natural evolution of atrophied 

 organs. The latter argument seems to me sufficient by itself 

 to settle in the affirmative the question whether acquired 

 characters and injuries are inherited. 



Moreover, it is self-evident that the injuries of a body are 

 not all hereditary to the same degree, and further, that in- 

 juries are inherited in different degrees in different animals. 



The idea naturally suggests itself that injuries affecting- 

 parts far removed from the centre of circulation parts less 

 richly supplied with blood are most likely to be inherited. 



The question of the inheritance of injuries is further closely 

 connected with that of the reproduction of parts removed 

 from the body : the lower the grade of organisation, the less 

 the degree to which division of labour is carried, the more 

 easily will such losses be repaired, the less probably will 

 injuries be inherited. Therefore it is to be supposed that 

 such inheritance will occur much oftener in the higher 

 animals than in the lower, scarcely at all in plants. 



We have now to enter upon the inheritance of diseases of 

 spontaneous origin. The negative standpoint in this question 

 has been advocated by my friend Ziegler in the paper above 

 cited, and in a lecture "On the Inheritance of acquired 

 pathological Characters and the Origin of inheritable Diseases 

 and Malformations." 1 He concludes that the former as well 

 as the latter arise always from changes in the germ. 



Ziegler holds that so long as it was assumed that fertilisa- 

 tion was a process in which a distribution and solution of 

 the spermatic substance in the ovum took place, the trans- 



1 Separate edition, from the Verhandlungen des Kongresses fur innere Medicin 

 in Wiesbaden, 1886. 



