H. Drinkwatbr 39 



Now these figures are very remarkable from their close approximation 

 to the same measurements in No. 1 family where they were respectively 

 58^ and 61 inches. 



The women are therefore about 4| inches and the men about S inches 

 below the normal height. 



It is the general opinion that the abnormals have better health 

 than their normal relatives. The abnormals are slightly more prolific 

 than the normals though the numbers are too small to enable one to 

 draw conclusions on this point. Increased fecundity was a marked 

 feature of No. 1 family. 



In both families a much larger proportion of normals have remained 

 unmarried. The schoolmistress stated that the parents of the boy 

 (No. 21) are cousins but such is not the case and I could not hear of 

 any intermarrying in the family. 



Mendelism. 



This family illustrates certain Mendelian rules : 



(1) There is perfect segregation. The abnormality is either not 

 transmitted or it is transmitted fully : i.e. so as to involve the digits 

 of both hands and both feet. 



(2) The abnormality is transmitted only by the abnormals and 

 never by the normals, so that all the descendants of normals are 

 normal. 



(3) The offspring of parents, OHe of whom is abnormal (= dominant) 

 the other normal (= recessive), should theoretically show 50 "7„ of each 

 type. The descendants, in this family, counting only those whose 

 type is known for certain, amount to 47, and of these 21 are abnormal : 

 i.e. 21 abnormals to 26 normals giving 446 insteail of the theoretical 



But this percentage is not to be regarded as positively correct. It 

 is certain that it is as high as this, but not at all certain that it does 

 not more closely approximate to the theoretical number. 



When I first interviewed the woman No. 9 in the chart she 

 informed me that of her ten children only one had short fingers like 

 her own, viz. her eldest daughter (No. 16) and a casual inspection 

 would have confirmed her statement. The shortening is so incon- 

 spicuous that in some of the children it is only detected by flexing 

 the finger, and then the shortened middle plialanx is noticeable but 



