title: Spaces precede axons in Xenopus embryonic spinal cord.
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure*; D002454:Cell Differentiation; D009412:Nerve Fibers / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology; D013116:Spinal Cord / Q000166:cytology*; D014982:Xenopus laevis