In order to examine the relationship between crowding and growth rate in green hydra (Hydra viridis), we raised animals at various levels of fixed population densities; all new individuals in excess ...

Article Published: 19 July 1947 Nutrition and Symbiosis* E. C. OWEN Nature 160, 78–81 (1947) Cite this article ...

IN NATURE of April 7 a short account is given of the interesting experiments made by Goetsch on the conversion of the green Hydra into a pale Hydra. Some years ago I observed what may be called a ...

Scientists already knew that the tiny aquatic creature Hydra vulgaris had to split its skin open every time it opened its mouth. Now, using a genetically modified organism made with contrasting ...