How did Morgan show the deviation in inheritance pattern in Drosophila with respect to this law?

Explanation

Morgan carried out dilybird crosses in drosophila to study genes that showed sex linkage. He hybridised yellow-bodied white eyed females to brown red eyes and carried out the study to `F_(2)` and noticed that the `F_(2)` phenotype ratio deviated from the `9:3:3:1` Mendel dihybrid `F_(2)` phonotypic ratio. Morgan used the genes that were both located on x-chromosome and summed up that the proportion of parental gene combinations is much higher than the non-parental one in case of physical association of genes or linkage of two genes.