title: On the development of the blood island in Xenopus laevis embryos: light and electron microscope study.
mesh_terms: D000818:Animals; D001001:Anura / Q000196:embryology*; D001773:Blood Cells; D002454:Cell Differentiation; D006413:Hematopoietic System / Q000196:embryology* / Q000254:growth & development; D008853:Microscopy; D008854:Microscopy, Electron