No. 590] TRANSMISSION OF DEGENERACY 69 



sterile. But none have ever given rise to a defective or 

 deformed individual, and the rate of mortality of the 

 young indicates the average healthy condition found in 

 normal guinea-pig breeding. There is a striking contrast 

 between the records of these normal young and the mor- 

 tality record, the frequency of easily recognized nervous 

 symptoms of degeneracy, and the prevalence of gross de- 

 formities in the experimental races. 



The external as well as internal factors are to be consid- 

 ered not only in individual or embryonic development, but 

 also in heredity. And the present experiments now dem- 

 onstrate for mammals that either the spermatozoon or the 

 ovum may be experimentally injured or modified in such 

 a manner as not only to give rise to (abnormal) sub- 

 normal development in the resulting embryo, but the 

 effects of the injury may be transmitted from generation 

 to generation, until an affected line actually fades out 

 through degeneracy and sterility as a result of the trans- 

 mitted condition. 



Mateeial and Methods 



The animals used in the experiments have been ordi- 

 nary vigorous guinea pigs of large size, particular care 

 being taken to select animals less than one year old to 

 begin with and good breeders. 



At the beginning of the experiments alcohol was given 

 along with the food, but the animals ate less and the food 

 usually disagreed with them. It was then administered 

 in diluted form by a stomach tube ; this method was even 

 more unsuccessful, disturbing digestion and seeming to 

 upset the animals considerably. It is certain that alcohol 

 given to animals through the stomach deranges their ap- 

 petite and digestion to such an extent that the experi- 

 menter is unable to determine whether the resulting ef- 

 fects are due to the alcohol, as such, or to the generally 

 deranged metabolism of the animal. When given in 

 drinking water they take little or none of the water and 

 the treatment is insufficient. For these reasons an inha- 



