Somatic and Germinal Variations 



at birth is probably largely germinal. According 

 to Weismann and the majority of zoologists, 

 there is a fundamental difference between these 

 germinal and somatic variations, in that the 

 former tend to be inherited, while the latter are 

 never inherited. Weismann believes that very 

 early in the formation of the embryo the cells 

 which will form the generative organs of the 

 developing organism are separated off from those 

 cells which will go to build up the body, and 

 become as much isolated from them as if they 

 were contained in a hermetically-sealed flask, so 

 that they remain totally unaffected by any 

 changes which the environment effects in the 

 somatic cells. Therefore, says Weismann, 

 acquired characters cannot be inherited. 



While the majority of zoologists believe that 

 acquired characters are not inherited, probably 

 not many will go so far as Weismann and 

 declare that the environment cannot exercise 

 any effect whatever on the germ cells. 



Even though acquired characters or variations 

 are not inherited, it does not follow that they do 

 not play an important part in evolution. Acquired 

 variations are the result of the way in which an 

 organism reacts to its environment. If an organ- 

 ism is unable to react to its environment it must 

 inevitably perish. If it is able to react, it matters 

 not, so far as the chances of survival of the 

 organism are concerned, whether the adaptation 



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