368 TRANSMISSION 



It is notable that all these experiments are based upon injury 

 to the nerve and are of a degree of severity likely to affect the 

 entire organism seriously. If, however, it is true that injury of 

 any kind in the parent leads, as Brown-Sequard and Romanes 

 evidently suppose, to corresponding deformities in the offspring, 

 the fact is exceedingly significant. This is a field, however, 

 quite different from that of ordinary injuries such as the 

 removal of a horn or a tail, producing no constitutional disturb- 

 ance and leading to no organic changes. Further experiments 

 are greatly needed to confirm, deny, or modify the results of 

 Brown-Sequard. In the meantime it seems almost incredible 

 that so much erroneous tradition should have grown up sur- 

 rounding this matter of inherited mutilations, especially when 

 the world for unknown generations has almost invariably seen 

 perfect children born from one-armed, one-legged, and otherwise 

 mutilated parents. Indeed, if offspring inherited the ordinary 

 mutilations of their parents, the world would have become long 

 since a collection of monstrosities which would put to shame the 

 rare specimens now collected in dime museums. 



Inheritance of disease. The old tradition of inheritance of dis- 

 ease is long since disproved, and those diseases once thought 

 to be inherited are now known to arise not from inheritance 

 but from infection after birth, which for obvious reasons is ex- 

 tremely easy between parent and offspring. 



The weakening effect of wasting diseases upon the parents, 

 and the influence of this weakening upon the constitution of the 

 offspring, inducing predisposition to disease, is, however, quite 

 another matter. That many of the effects of such a disease of 

 the parents will work injury and weakness to the offspring will 

 be readily admitted ; that such offspring will be the more sus- 

 ceptible to attack from diseases of all kinds will hardly be 

 denied ; but whether it will be peculiarly susceptible to the spe- 

 cial disease that wrought havoc with the parent is a question 

 on which we need much more evidence. 



Up to date this point has not, in the opinion of the writer, 

 been established. Although it is true that certain family lines 

 are specially susceptible to tuberculosis, it is not yet shown 

 whether this susceptibility is the result of inroads of this special 



