title: Studies of oogenesis in Urechis caupo. I. Method for separating different size classes of oocytes.
mesh_terms: D000818:Animals; D000845:Annelida / Q000196:embryology*; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D005260:Female; D010063:Ovum / Q000166:cytology / Q000254:growth & development*