HEREDITY 167 



exposure, a man and his wife both contract marked 

 chronic bronchial irritability. In such a case the 

 chance of their children being similarly affected would 

 be very great. If we admit, as we certainly must, the 

 transmission from parent to child of peculiarities of 

 form and structure, we cannot by any method of 

 reasoning limit such transmission to external appear- 

 ances only. All that applies in this respect to each 

 part as a whole must inevitably apply to its minute 

 conformation and general condition also, to the 

 individual cells as well as to the collection. 



When the abnormal state of any tissue assumes a The 

 chronic character, so that it reacts upon the nervous tranamis- 

 system, and causes it to function in an irregular syphilis. 

 manner, it is very likely to be transmitted. The 

 transmission may not be in the same degree, and 

 there is always the possibility of a child inheriting the 

 character of this or that part or organ from one 

 parent only, but there can be no doubt as to the 

 transmissibility in many cases of acquired character- 

 istics. Weaknesses which have become grafted, so to 

 speak, on to the nervous system, even though not 

 causing suffering at the time of generation or 

 affecting the parent to any appreciable extent, may 

 nevertheless be transmitted to the offspring. This is 

 notably the case in syphilis, the whole character and 

 peculiarities of which are easily explained if we look 

 on it as modifying the nutritive action of the nervous 

 system in a katabolic sense, and as being frequently 

 transmitted as a nervous affection of that nature to 



