Experimental studies have shown that the myogenic stem cells in birds migrate from the somite into the lateral plate mesoderm, where they later differentiate into muscle cells. Muscles being made up of myocytes and connective tissue cells, the interactions between these two types of cells of different embryological origins have been considered during the development of the musculature. In particular, our purpose was to focus on the genesis of the spatial organization of the musculature; we have taken advantage in this field of research of an embryological muscular dysgenesis in which the muscles lose their patterning.