|Dugout K Howell Pastel on Paper 21 cm x 14 cm|
The life of a tree depends on the journey of water through its vascular system. A tree trunk consists mostly of dead xylem tissue. (Botanists may want to look away now.) Xylem cells are alive when initially produced by the meristematic cambium, but when they become functioning water-conducting cells, they lose their cell contents and become hollow, microscopic tubes with woody walls. Water is primarily pulled upward due to the cohesion of water molecules through the plant's vascular system from roots to leaves. As water molecules move out through the stomata (tiny pores) into the atmosphere, they are replaced by new molecules entering the roots from the soil. More or less.
When a tree trunk is dug out, most of the vascular tissue is removed, and the tree itself becomes a vessel for all kinds of journeys. Dugout boats are the oldest boats archeologists have found, probably because they preserve well, being constructed from a single tree. The Iron Age Poole log boat is a fine example. Early Bronze Age 'ship' burials (the Gristhorpe Man) prepared the departee with weapons and food for the trip, encased within a hollowed-out tree trunk. According to Gerald of Wales (Liber de Principis instructione c.1193), the body of the elusive King Arthur was discovered 'hidden deep in the earth in a hollowed-out oak bole' in the grounds of Glastonbury Abbey.
In Norse mythology Ask and Embla , the first humans, are brought forth from trees. From womb to tomb, there is growth and journey. Touch Wood.