88 GENETICS 



ever be accused of wearing shoes or of having had 

 shoe- wearing ancestors. 



Sheep and horses with docked tails as well as dogs 

 with trimmed ears never produce young having the 

 parental deformity. Weismann's classic experiment 

 with mice, an experiment subsequently confirmed 

 by others, is additional negative evidence upon this 

 same point. 



What Weismann did was to breed mice whose 

 tails had been cut off short at birth. He continued 

 this decaudalization through twenty-two generations 

 with absolutely no effect upon the tail-length of the 

 new-born mice. One may see in the catacombs of 

 the Zoologisches Institut at Freiburg, filed carefully 

 away on shelves, as a " document," long rows of labeled 

 bottles containing the fifteen hundred and ninety-two 

 martyrs to science which made up the twenty-two 

 generations of mice in this famous experiment. 



Conklin has hit the nail upon the head with respect 

 to mutilations by saying: "Wooden legs are not in- 

 herited, but wooden heads are." 



b. Environmental Effects 



Trees deformed by prevailing winds, like the 

 willows that line the canals in Belgium and Holland, 

 or storm-crippled trees along the exposed seacoast 

 are not known to produce a modified progeny 

 when their adverse environmental conditions are 

 removed. Similarly, the persistent sunburn of Eng- 

 lishmen long resident in India does not reappear in 

 their children born in England. 



