ARE ACQUIRED CHARACTERS HEREDITARY? 425 



ties in their gait and other signs of nystagmus. Moreover, the young 

 of parents rotated to the left showed different effects from those of 

 parents rotated to the right. The condition is said to have been 

 inherited for several generations. Detlefson, however, noted that the 

 whirled rats and their offspring showed frequent pathological sequelae, 

 such as discharges from the ears, and is now inclined to wonder 

 "whether Griffith has not merely presented us with numerous speci- 

 mens of some vertebral disease." The implication is that the disease 

 once started might be passed on to future generations by infection. It 

 is generally understood that Detlefson has been repeating these experi- 

 ments upon the Wistar Institute standard white rats, and that his 

 results are so far negative. 



And thus stands the problem today. It is no more settled than 

 it was fifty years ago, but most of us are growing to be a little pessi- 

 mistic about the whole matter. 



