356 THE POPULAR SCIENCE MONTHLY. 



HEEEDITY. 



By GEORGE ILES. 



HAWTHORNE in his masterpiece, the " Scarlet Letter," makes 

 his heroine, Hester Prynne, a woman who has sinned, resolutely 

 refuse to tell the name of her partner in guilt when the Puritan in- 

 quisitors urge her to do so. The ministers of justice and vengeance 

 then turn to her child, and sharply scrutinize her features, to find if 

 possible some trace of her father's look, that the wrong done may be 

 punished. Here, too, they are unsuccessful — the face of the little elf 

 tells no story that they can read, gives them no clew in their task of 

 detection ; they are obliged to withdraw, baffled and surly. This inci- 

 dent in the greatest of American romances is true to experience ; 

 while the inheritance from parents of form and character is general, 

 yet it is not universal, and while some of the exceptions, when ex- 

 plained, afford very interesting studies of the play of natural forces, 

 too subtile to be noticed by simple inspection of their results, yet 

 many anomalies exist in heredity w^hich the science of to-day is quite 

 incompetent to explain. 



The inheritance of the peculiarities of physical structure is a mat- 

 ter of daily and hourly observ-ation, and the minute fidelity of it is at 

 times very remarkable. Agassiz placed on record cases where traces 

 of surgical operations had been transmitted. Sometimes parent and 

 child are not only alike in form and feature, but even in tricks of tone 

 and gesture, handwriting and gait. 



The predisposition to certain diseases, like gout or insanity, often 

 developed after maturity, is transmissible ; and also the liability to die 

 about a certain age. The famous Turgots, for more than a century, 

 rarely exceeded fifty years of age ; and insanity often appears after the 

 meridian of life in several successive generations of a family. The 

 remarkable faithfulness of reproduction in the majority of cases is a 

 fact somewhat parallel to the growth and maintenance of an organism, 

 Avherein, with the constant succession of cells each of brief existence, 

 substantial identity is kept up. There do not seem to be very marked 

 differences in babes, yet from the same food one will become a man of 

 muscle and energy, another of nerve and brain, a third a portly man 

 of ease-loving habits. All the original peculiarities of each tiny hu- 

 man nucleus pick out from a common nourishment elements like them- 

 selves, rejecting the rest. 



Inheritance is not only physical, but inte'llectual as well ; great 

 ability in mathematics, painting, music, and other departments of 

 effort, has clearly been received at birth in many thousands of exam- 

 ples. The Bach family for two hundred years maintained exalted rank 

 in music. Tiie direct succession of very able men in the families of 



