84 GENETICS 



(2) That in most cases the marks or defects whose 

 origin is attributed to maternal impression, must 

 necessarily have been complete long before the incident 

 occurred which the mother, after the child's birth, 

 ascribes as the cause. 



(3) That these phenomena usually do not occur 

 when they are, and by hypothesis ought to be, expected. 

 The explanations are found after the event, and that 

 is regarded as causation which is really coincidence. 



It is easily understandable that any event which 

 makes such an impression on the mother as to affect 

 her health, might so disturb the normal functioning of 

 her body that her child would be badly nourished, or 

 even poisoned. Such facts undoubtedly form the basis 

 on which the airy fabric of prenatal culture was reared 

 by those who lived before the days of scientific biology." 



C. THE GEEMPLASM THEORY SUFFICIENT TO ACCOUNT 

 FOE THE FACTS OF HEREDITY 



Weismann holds that the theory of the continuity 

 of the germplasm, already considered in a previous 

 chapter, is sufficient in itself to account for the facts 

 of heredity. Hence it is quite unnecessary to fall back 

 upon the inheritance of acquired characters as an 

 explanation, since this theory is at least difficult, if 

 not impossible, of satisfactory proof. 



To prove the inheritance of acquired characters, 

 according to Weismann three things are necessary: 

 first, a particular somatic character must be called 



