Tiny Spider Central Nervous Systems (IMAGE) Smithsonian Tropical Research Institute Caption The brains of smaller spiders, like nymphs in the genus Mysmena, extend out of their body cavity into their legs. Credit Wcislo lab. Usage Restrictions Credit: STRI License Licensed content 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.