I30 THE BIOLOGY OF TWINS 



of these halves resembles the maternal condition. For 

 tables showing all the data upon which this discussion 

 is based the reader is referred to a special paper on the 

 inheritance of numbers of scutes.^ There a study of 

 inheritance was made for each of the five armor regions. 

 What has been said for the banded region applies equally 

 well to the other four shields. 



A general conclusion from this intricate and exten- 

 sive mass of statistical data is that both large and 

 small groups of integral variates, such as the aggregate 

 of scutes in an armor shield or a single band, are inherited 

 primarily according to the Mendelian laws of dominance, 

 with only a minor degree of blending, and that the 

 dominance is regional and not very often general for a 

 large section of armor. This, then, is a sort of particu- 

 late inheritance, a mode of inheritance which implies a 

 somatic segregation of parental characters. 



When biometrical methods of inheritance study 

 are applied to this material, certain new facts are 

 brought out, but certain other facts already seen for 

 individual cases are reduced to general terms and are 

 likely to be lost sight of. 



Correlation between mothers and of spring as to 

 numbers of scutes. — -By the use of standard statistical 

 methods the coefficients of correlation between mothers 

 and offspring have been derived for a large number of 

 characters. To illustrate: it was found that, with 

 respect to the total number of scutes in the banded 

 region of armor, there was a coefficient of correlation 

 between mothers and 56 sets of male quadruplets of 

 0.5522=1=0.0625, and for 59 sets of female quadruplets, 



^ H. H. Newman, loc. cit. 



