193 



and that most materially supported by experience, is here- 

 ditary transmission. Undoubtedly various forms of scrofulous 

 as of tubercular disease run in families. Every practitioner 

 must be cognisant of the fact that the parents of scrofulous 

 children were themselves, in many instances, also scrofulous 

 in their early age, and that phthisical parents very frequently 

 generate scrofulous children. Although statistics may not 

 count for much, yet Lebert was able to prove hereditary 

 transmission in one-third of eighty-eight cases. Balman 

 ascertained that among 141 scrofulous patients nine had lost 

 the father, and eleven the mother, of tuberculosis ; while 

 thirty cases of tuberculosis had occurred in near or distant 

 relatives of the rest. 1 It must therefore be conceded that 

 from first to last, amid all its sources and varieties, amid all 

 its developments and retrogressions, in whatever form it may 

 assume, amid all its degrees and complications, heredity is 

 the prime factor in the production of scrofulosis, as it is also 

 in tuberculosis. 



Diabetes Mellitus. But a few decades ago, anyone who 

 would have ventured to include heredity as a predisposing 

 cause of this affection would have probably been treated 

 with ridicule. Since, however, greater attention has been 

 directed to the matter in more recent times, the result of 

 constantly accumulating experience is undoubted and in- 

 creasing testimony in regard to the hereditary character of 

 diabetes. Not only have several of the brothers and sisters 

 in certain families become diabetic, but instances are 

 recorded where every child has been the subject of this 

 disease. Moreover, it has been frequently observed that 

 parents, or grand-parents, suffering from the disease, have 

 transmitted a -predisposition to their children and grand- 

 1 Ziemssen. 



