HEREDITY AND HUMAN IMPROVEMENT 377 



in man as in animals. Two albinos will produce nothing 

 but albino offspring. 



Deafness is sometimes a hereditary and sometimes an 

 acquired character. When it is due to accident or disease 

 there is little danger of its transmission, but when it is 

 caused by some inborn defect it is very apt to afflict 

 the following generation, especially if both parents are 

 congenitally deaf. 



It often happens that there may be a strong proclivity 

 toward some defect or disease which may be overcome 



FIG. 248. Diagram illustrating the inheritance of insanity and 

 other forms of mental defect, i, alcoholic; 2, feeble minded; 3, feeble 

 minded; 4, hypochondriac; 5, had insane daughter; 6, visionary, drunken 

 wreck; 7, eccentric; 8, insane; 9, unbalanced; 10, crazy, fits of temper, 

 gets wild; n, insane; 12, microcephalic, defective, died in infancy; f 

 died in childhood. (Prom data from Rosanoff and Orr.) 



by wholesome living under favorable conditions. It is 

 commonly held that people may inherit a tendency 

 toward tuberculosis, gout, Bright's disease and numerous 

 other maladies; but if a person takes the proper precau- 

 tions he may avoid these impending dangers. Knowledge 

 of hereditary predispositions is often of great service 

 to the physician in understanding his patient's case, 

 especially if he is dealing with nervous or mental ailm nts. 

 That heredity plays an important role in the production of 

 insanity has long been recognized, but it is only recently 

 that evidence has been brought forward to show that 



