Filaments of Tortotubus (image) University of Cambridge Share Print E-Mail Caption Three filaments of Tortotubus from Gotland, Sweden, showing growth of secondary branches along main filament. Transmitted Light Micrograph. Credit Martin R. Smith Usage Restrictions Please credit to Martin R. Smith Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.