This method of Sewall Wright was worked out for studying mathematically and by diagrams, the paths of genes in populations and genetic events determining multiple correlations. Here it is not possible to discuss meaningfully the mathematical foundations but one type of graphic application for determining some relations between offspring and parents can be found under F and inbreeding coefficient.  inbreeding coefficient,  correlation; Wright S 1923 Genetics 8:239; Wright S 1934 Ann Math Stat 5:161.