Possessing neither blood nor brain, jellyfish are primarily filled with a jelly-like substance loaded with nerve cells that help them navigate the seas. These cells detect light and touch, and then pass this information on to muscle cells. In all its simplicity, the jellyfish has existed for more than 600 million years with little change. Perhaps the jellyfish is indeed nature's perfect beast.

水母既没有血液也没有大脑，主要由满是胶状物质的神经细胞来协助它在海中的航行。这些细胞能侦测光线和触觉，然后把信息传达到肌肉细胞。 虽然水母的结构很简单，它已经在地球上存在超过六亿年了，而且没有什么改变。也许水母真的是自然界中真正的霸主。

(短文节选,本篇始于：海中“刺”客──水母)