384 EXPERIMENTAL STUDY OF INHERITANCE 



mean of which the offspring of divergent members showed a 

 tendency to approximate, but this mean is different from that 

 of the general population. In other words, selection of quan- 

 titative characters within a " pure line " is not effective like 

 selection in a population. 



Blended Inheritance. — The progeny of a white and a black 

 is a mulatto, and mulattos intermarrying breed true, neither 

 white nor black reappearing. It is a clear case of blended in- 

 heritance, and of blended inheritance remaining stable. And 

 this applies to the hair as well as to colour. When mulatto 

 marries white, there is again a blend. When mulatto marries 

 black, there is again a blend. There is not the least hint of 

 Mendelian inheritance. Similarly in quite a number of hybrid- 

 isations — e.g. dog and jackal, horse and ass, lion and tiger, brown 

 bear and polar bear — there is blending, though one parent may 

 be more or less prepotent. 



Half-bred Sheep. — An experienced breeder, Mr. John Man of 

 Uppermill, Tarves, Aberdeenshire, has expressed to me his con- 

 viction that the Mendelian formula does not apply, for instance, 

 to the case of half-bred sheep. 



" Border Leicester rams mated with Cheviot ewes produce 

 half-bred lambs, and these when mated with each other con- 

 tinue in successive generations to breed true to their own type 

 with very little (if any ?) tendency towards either of the parent 

 breeds." 



Particulate Inheritance. — There is no doubt that in some 

 cases the offspring of two more or less different parents may 

 show the characters of one parent in one part of the body and 

 the characters of another parent in another part of the body, — 

 i.e. particulate inheritance— g.g'. in piebald horses, cattle, dogs, 

 etc. A cross between a red and a white flower may be a white 

 flower with red stripes or vice versa. Correns refers to the 

 popular impression that this mode of inheritance is very common 

 and says that this is very far from being the case. Where 



