Essays on Life 



tures mutilated by injuries or altered by 

 disease, it was until lately difficult to come 

 to any definite conclusion." [Then follow 

 several cases in which mutilations practised 

 for many generations are not found to be 

 transmitted.] " Notwithstanding," continues 

 Mr. Darwin, "the above several negative 

 cases, we now possess conclusive evidence 

 that the effects of operations are sometimes 

 inherited. Dr. Brown- Sequard gives the fol- 

 lowing summary of his observations on guinea- 

 pigs, and this summary is so important that 

 I will quote the whole : 



" ' 1st. Appearance of epilepsy in animals 

 born of parents having been rendered epileptic 

 by an injury to the spinal cord. 



" ' 2nd. Appearance of epilepsy also in ani- 

 mals born of parents having been rendered 

 epileptic by the section of the sciatic nerve. 



" ' 3rd. A change in the shape of the ear in 

 animals born of parents in which such a 

 change was the effect of a division of the 

 cervical sympathetic nerve. 



"'4th. Partial closure of the eyelids in 



animals born of parents in which that state 



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