title: The extent of cell contact and the relative frequency of small and large gaps between presumptive mesodermal cells in normal gastrulae of Rana pipiens and the arrested gastrulae of the Rana pipiens female x Rana catesbeiana male hybrid.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002449:Cell Aggregation; D002454:Cell Differentiation; D002465:Cell Movement; D006822:Hybrid Cells; D011892:Rana catesbeiana / Q000196:embryology; D011894:Rana pipiens / Q000196:embryology