2o 4 TRANSMISSION OF ACQUIRED CHARACTERS 



by any of the accidents and incidents in the daily life of the body 

 which is their bearer. But no one believes this, Weismann least 

 of all, for he finds the chief source of germinal variations in the 

 stimuli exerted on the germ-plasm by the oscillating nutritive 

 changes in the body. 



Weismann's Concessions. — There are some who find in this 

 " a concealed abandonment of the central position of Weismann," 

 and who say : "If the germ-plasm is affected by changes in 

 nutrition in the body, and if acquired characters effect changes 

 in nutrition, then acquired characters or their consequences 

 will be inherited." But it is quite illegitimate (§ 5) to slump 

 acquired characters and their consequences as if the distinction 

 were immaterial. The illustrious author of The Germ-Plasm has 

 made it quite clear that there is a very great difference between 

 admitting that the germ-plasm has no charmed life, insulated 

 from bodily influences, and admitting the transmissibility of 

 a particular acquired character, even in the faintest degree. The 

 point, let us repeat, is this : Does a structural change in a part 

 of the body, induced by use or disuse, or by change in surround- 

 ings, influence the germ-plasm in such a specific or representative 

 way that the offspring will thereby exhibit the same modification 

 that the parent acquired, or even a tendency towards it ? 



The Real Difficulty. — Even when we recognise, as fully as we 

 can, the unity of the organism, that each part shares in the life 

 of the whole, it is very difficult to think of any modus operandi 

 whereby a local modification can specifically affect the germ- 

 plasm. The argument that we can as little understand the 

 modus operandi whereby an influence passes from the gonads 

 to distant parts of the body is not really sound. For we know 

 that in some cases the reproductive organs, besides being areas 

 for the multiplication of germ-cells, are organs of internal secre- 

 tion, producing specific substances which are carried away by 

 the blood-stream, and serve as the stimuli awakening the dormant 

 potentialities of distant parts. 



