THE STUDY OF INHERITANCE. 619 



Inheritance is unfortunately a word which is not always used 

 with scientific precision. Most of the qualities which give a horse 

 its value, as compared with other horses, are due to breeding, but 

 this word has many meanings. Orlando says : " His horses are 

 bred better ; for besides that they are fair with their feeding, they 

 are taught their manage, and to that end riders dearly hired." 

 The "breeding jennet, lusty, young, and proud," seems to be a 

 wild mare, with no breeding in the first sense, and the horse which 

 did not lack what a horse should have, "round-hoofed, short- 

 jointed, fetlocks shag and long. Broad breast, full eye, small 

 head, and nostrils wide. High crest, short ears, straight legs, and 

 passing strong. Thin mane, thick tail, broad buttocks, tender 

 hide," is a thoroughbred. 



Recent speculations have enforced attention to the difference 

 between these meanings of the word. In the last sense breeding 

 is the influence of ancestry, and it may practically be treated as 

 synonymous with the word ancestry. 



In the first sense breeding, broadly used, is that influence of 

 the ontogenetic environment for which that most objectionable 

 term " acquired characters " has been thoughtlessly adopted. 



In his earlier writings Galton, borrowing, I suppose, from the 

 Tempest, uses the word " nurture " to designate it, and this term 

 is so apt and expressive that it should not pass out of use, for it 

 may be given a definite technical meaning without violence to its 

 ordinary use. 



Using nurture instead of acquired characters for the influence 

 of the environment of the individual, we may speak of the two 

 elements of breeding as ancestry and nurture. 



At the present day it is obvious that our studies of inheritance 

 can have little value unless we distinguish between these two 

 factors, for many naturalists hold that there is good ground for 

 questioning whether the effects of nurture are ever inherited, and 

 most naturalists admit the possibility that the value of these two 

 factors may be very different. 



If breeding is to be studied by the statistical method for the 

 purpose of exhibiting the laws of inheritance, we must employ 

 types in which we can separate the effects of ancestry from the 

 effects of nurture ; for if we make use of types which do not admit 

 of this analysis, our results may tell us no more of inheritance 

 than the scheme of prices tells us of the value of blood in horses. 



If, as many teach, inheritance is equivalent to ancestry, and 

 nurture is not inherited, no type in which these two factors are 

 combined can tell us anything about inheritance. 



It seems probable from Galton's data regarding the resem- 

 blance between the finger marks of fraternal couples that this is 

 due to nurture in the broad sense of the word, and not to inherit- 



