Embryonic morphogenesis: role of fibrous lattice in the development of feathers and feather patterns.

In the morphogenesis of embryonic feather germs the formation of dermal cell groupings is associated with the development of a highly regular pattern of birefringence in the dermis. This birefringence is due to a lattice-like system of collagenous tracts along which dermal cells become progressively aligned and grouped in regularly spaced sites. The experimental results suggest that this fibrous lattice is of major significance in the morphogenesis of feather germs and in their characteristic pattern of distribution.