translation.en: There are species that have no aging -- Hydra for example -- but they do it by not having a nervous system -- and not having any tissues in fact that rely for their function on very long-lived cells.
translation.zh: 有些物种没有老化。例如水螅 – 因为他们没有一个神经系统 – 也没有任何用于老化的的细胞 却有长寿的细胞组织。