title: Structure development in aggregens.
mesh_terms: D000818:Animals; D002449:Cell Aggregation; D003228:Conjunctiva / Q000196:embryology*; D046508:Culture Techniques; D000882:Haplorhini; D006367:HeLa Cells; D006321:Heart / Q000196:embryology*; D006801:Humans; D007668:Kidney / Q000196:embryology*; D008099:Liver / Q000196:embryology*; D008198:Lymph Nodes / Q000196:embryology*; D051379:Mice; D013552:Swine