THEORY OF EVOLUTION 33 



acquired characters rested. Your neighbor's 

 cat, for instance, has a short tail, and it is said 

 that it had its tail pinched off by a closing door. 

 In its litter of kittens one or more is found 

 without a tail. Your neighbor believes that 

 here is a case of cause and effect. He may even 

 have laiown that the mother and grandmother 

 of the cat had natural tails. But it has been 

 found that short tail is a dominant character; 

 therefore, until we know who was the father of 

 the short-tailed kittens the accident to its 

 mother and the normal condition of her mater- 

 nal ancestry is not to the point. 



Weismann appealed to common sense. He 

 made few experiments to disprove Lamarck's 

 hypothesis. True, he cut off the tails of some 

 mice for a few generations but got no tailless 

 offspring and while he gives no exact measure- 

 ments with coefficients of error he did not ob- 

 serve that the tails of the descendants had 

 shortened one whit. The combs of fighting 

 cocks and the tails of certain breeds of sheep 

 have been cropped for many generations and 

 the practice continues today, because their tails 

 are still long. While in Lamarck's time there 



