title: Effect of germanium upon development of siliceous spicules of some fresh-water sponges.
mesh_terms: D000818:Animals; D005618:Fresh Water; D005857:Germanium / Q000494:pharmacology*; D008858:Microscopy, Phase-Contrast; D011161:Porifera / Q000187:drug effects*; D012822:Silicon Dioxide / Q000378:metabolism
chemical_list: D005857:Germanium; D012822:Silicon Dioxide