70 LECTURES 



hands and feet, and the six-fingered father of the child 

 refused to recognize the last one as his own." I must let 

 an example of this kind stand as a representation of the 

 thousand and one other characters that are inherited by 

 children from their ancestors in every part of the world. 

 Indeed, this matter of inheritance in so very common, 

 both in the case of normal characters as well as abnormal 

 ones or even in diseases or the predisposition to the same, 

 also habits and traits, that they are scarcely noticed in 

 our everyday life. All animals and plants exhibit the 

 same tendency, and instead of it being a matter of light 

 import the entire law is one of the very greatest biologi- 

 cal importance, and has been dealt with under the gen- 

 eral law of heredity and inheritance; the first having 

 reference to the power of transmission and the latter to 

 actual transmission. These when taken in connection 

 with the now well-proved fact of the mutability af 

 organisms, it at once becomes apparent to any one of us 

 how important it is to well examine and study the re- 

 sulting phenomena. This applies especially to the 

 biologist, and to the scientific and thoughtful physician. 

 Connected with this law we have to deal with another, 

 or the one referring to the question of the alternation of 

 generations, where inherited characters are known to skip 

 one or more generations; and this law, pushed to the ex- 

 treme, explains the matter of reversion or atavism. An 

 excellent illustrative example of the last are those cases 

 wherein we sometimes see a horse born with series of dis- 

 tinct stripes of black arranged in a definite way on the 

 body and limbs. No such character ever occurred in its 

 ancesters so far as they can be traced back, and the con- 

 dition can alone be explained by atavism, or in other 

 words the original stock of all of the horses from which 

 such an individual is descended was a striped animal or 

 a striped race or family, something like the now wild 

 zebras, quaggas, etc. existing horse-like animals in Na- 

 ture. In ages to come such cases of atavism will un- 

 doubtedly, and not unfrequently, arise through inter- 

 marriage of the hybrid descendants among us of 

 Ethiopian and Caucasian stock. One has but to study in 

 this city the very numerous and extremely light-colored 

 hybrids of Afro-Caucasian species which are now annu- 

 ally making their appearance to understand this. In fact, 

 I have collected one good example of this for use in my 

 anthropological studies. A man of undoubted Saxon des- 

 cent married a woman as white as himself, and whose 

 ancestors had been white for a generation or two before 



