title: Ultramicroscopic filaments in the ascidian Botryllus schlosseri (Pallas) and their possible role in ampullar contractions.
mesh_terms: D000818:Animals; D001639:Bicarbonates; D002816:Chordata, Nonvertebrate / Q000033:anatomy & histology*; D006652:Histological Techniques; D008675:Metamorphosis, Biological; D008854:Microscopy, Electron; D009040:Motion Pictures; D009119:Muscle Contraction; D013997:Time Factors
chemical_list: D001639:Bicarbonates