So with air. If there is not a sufficient depth, it cannot support large birds. And for this bird a depth of ninety thousand _li_ is necessary; and then, with nothing save the clear sky above, and no obstacle in the way, it starts upon its journey to the south. A cicada laughed, and said to a young dove, "Now, when I fly with all my might, 'tis as much as I can do to get from tree to tree. And sometimes I do not reach, but fall to the ground midway. What then can be the use of going up ninety thousand _li_ in order to start for the south?" He who goes to Mang-ts'ang, A short distance into the country. taking three meals with him, comes back with his stomach as full as when he started. But he who travels a hundred _li_ must grind flour enough for a night's halt. And he who travels a thousand _li_ must supply himself with provisions for three months. Those two little creatures,--what should they know? Small knowledge has not the compass of great knowledge any more than a short year has the length of a long year. How can we tell that this is so? The mushroom of a morning knows not the alternation of day and night. The chrysalis knows not the alternation of spring and autumn. Theirs are short years. But in the State of Ch'u there is a tortoise whose spring and autumn are each of five hundred years' duration. And in former days there was a large tree which had a spring and autumn each of eight thousand years' duration. Yet, P'êng Tsu The Methusaleh of China. His age has not been agreed upon by Chinese writers, but the lowest computation gives him a life of eight hundred years. is still, alas! an object of envy to all. It was on this very subject that the Emperor T'ang B.C. 1766. spoke to Chi, as follows:--"At the barren north there is a great sea, the Celestial Lake. In it there is a fish, several thousand _li_ in breadth, and I know not how many in length. It is called the Leviathan. There is also a bird, called the Rukh, with a back like Mount T'ai, China's most famous mountain, situated in the province of Shantung. and wings like clouds across the sky. Upon a typhoon it soars up to a height of ninety thousand _li_, beyond the clouds and atmosphere, with only the clear sky above it. And then it directs its flight towards the south pole. "A quail laughed, and said: Pray, what may that creature be going to do? I rise but a few yards in the air, and settle again after flying around among the reeds. That is the most I can manage. Now, where ever can this creature be going to?" The repetition of this story, coupled with its quotation from the _Record of Marvels_, is considered to give an air of authenticity to Chuang Tzŭ's illustration, which the reader might otherwise suppose to be of his own invention.