INTRODUCTION 3 



the thoroughbred racer. No one animal could possess 

 the qualities of all three. 



From the practical point of view of daily life, the 

 influence of heredity is constantly taken into account. 

 An acquaintance with the family is found to give an 

 insight and a completion to our knowledge of the 

 individual, his capacities, his character, his strong 

 points and his failings. A man of whose parentage 

 and antecedents nothing is known remains of necessity 

 a stranger long after he himself has ceased to provide 

 any cause for surprise or suspicion. Yet when his 

 offspring stand before us, the surprise may return and 

 deepen into dismay, and the suspicions which had been 

 lulled into forgetfulness may arise and transform them- 

 selves into some lamentable certainty. 



The family may be considered from many points of 

 view. It has a political aspect, a romantic aspect, an 

 economic aspect, a religious aspect. From each of 

 these points of view it has been considered by the 

 leaders of thought of every succeeding generation. 

 But, during the last century, which may be called the 

 scientific age, while the co-ordination of natural know- 

 ledge has gradually been illuminating many of the 

 dark places of the human intelligence, we have come 

 to see that the family has also a scientific or biological 

 aspect. From this last standpoint, especially in the 

 light of our growing knowledge of heredity, we are 

 chiefly to deal with it here. 



Time was and not many decades ago when the 

 biological views of Lamarck of the inheritance by 

 offspring of characteristics acquired during life by 



