WEISMANN'S THEORY OF HEREDITY 71 



The sagacity which set those opponents by 

 the ears is still available. There is no attempt 

 to untie that knot; Weismann cuts it with a 

 knife. He empties his antagonist's sails by a 

 smiling and gracious surrender. Below the 

 sexually reproducing animals, he concedes the 

 operation of the Lamarckian factor. In that 

 unicellular world it is not a special cell that 

 is passed on but the individual itself is con- 

 tinued, and of course any character acquired 

 by the individual will be preserved along with 

 the individual. 



Thus then the region of controversy is lim- 

 ited to sexually reproducing organisms and 

 we come to the field where the fiercest fight 

 was made. Do these organisms transmit by 

 heredity those characters or peculiarities ac- 

 quired by the individual during its own life- 

 time? To this question the Neo-Lamarckians 

 gave a positive affirmative, which Weismann 

 met with an unwavering denial. 



Weismann challenged his opponents to pro- 

 duce a single demonstration of such a trans- 

 mission. Here let us be clear as to what is 

 meant by an acquired character. For illustra- 

 tion, let us suppose a father leaves his son an 

 estate of a thousand acres. That is inherit- 

 ance. If the son leaves his son the same one 

 thousand acres, that is still inheritance. But 



