The life of the species, then, the Odyssey of the species through timehas transpired, like the maturation of Eiseley himself, within the shadowof a “non-existent tree.” Born amidst “earth’s leafy shadows,” having de-scended from the trees to become world conquerors, the prodigal, too,seems to have left its home in the natural world far behind him in thecourse of his immense journey. But the natural world still calls out to himto return, as if he had a future appointment with it that he has forgotten.The human mind is tethered to the Earth, inextricably under the sway ofa geologic, just as Eiseley’s mind was tethered to his tree, and evolution isthe tether, and the symbol of the tethering is a tree:We today know the results of Darwin’s endeavors—the knitting to-gether of the vast web of life until it is seen like the legendary tree ofIgdrasil, reaching endlessly up through the dead geological strata withliving and relevant branches still glowing in the sun (1969, p. 133).In Norse mythology, Igdrasil, the world tree, a mythic “image of widescope,” unites within its roots and branches all things: heaven, earth, andthe underworld. So, too, Igdrasil in a sense is meant: for it has only beenthrough the human mind that the “web of life” becomes known—becomesconscious of itself. Thus Eiseley the “druid seer” recognized that as anindividual he was an Igdrasil as well:I too am aware of the trunk that stretches loathsomely back of me alongthe floor. I too am a many-visaged thing that has climbed upward out ofthedarkofendlessleaffalls,andhasslunk,furred,throughtheglitterofblue glacial nights. I, the professor trembling absurdly on the platformwith my book and spectacles, am the single philosophical animal. I amthe unfolding worm, and mud fish, the weird tree of Igdrasil shapingitself endlessly out of darkness toward the light (1975b, p. 168)