In James Joyce’s “Ulysses,” the hero Stephen Dedalus imagines making a telephone call to Eden using an umbilical cord as a cable. The humor of the scene derives from the wry disregard that most Westerners have for this most curious of temporary appendages, this ultimate reason for the belly-button.

(Also, of course, there’s the ironic observation which is sometimes made, that Eden’s human inhabitants presumably didn’t have umbilical cords . . . )

If the bulk of Joyce’s readers were Japanese, however, and had a more serious “attachment” to this bundle of tissue, would the scene be quite so comic? So attached are the Japanese to their umbilical cords that many never relinquish them. That’s right, they still have them! Well, in a box, that is.

This isn’t as peculiar as it may sound to the uninitiated. The entire umbilical cord is not preserved, merely a portion of it. This part shrinks as it dries out, becoming small enough to be stored in a small container — a nice lacquered box being the vessel of choice.

Skeptics should ask a Japanese friend. Without blinking — perhaps with some confusion as to why you would be inquiring about the obvious — they will confirm that they do indeed have their heso-no-o (lit. “tail of the belly”). If they don’t, their mothers probably do. Most are willing to show it without any inhibitions.

Ask them why they keep it and the explanation most likely to be offered is that the cord deserves to be honored and saved for posterity because it is a link to one’s mother. This is a notion rooted in Japan’s strong and sentimental views on the connection between a mother and her child, even into adulthood.

The country’s folklore scholars, however, are mum on the matter. In her book “Jiyarai,” for example, noted author Yuki Ohto (an esteemed member of the Japan Folklore Society) devotes just two pages to the subject. Her brief account of the heso-no-o makes no mention of the origins of the practice of preservation. Instead, she enumerates the various related customs from different parts of Japan.

Traditions in several parts of Japan called for using special types of bamboo to sever the connecting cord. In other areas, directions are given as to how much should be cut and retained, citing the size of the baby’s heel, knee or hand as proportional measurements.

It is in these nearly-forgotten customs that we perhaps catch a glimpse of how it all began. One practice was to bind the cord tightly with cloth, severing its blood supply until it finally fell away. Could a mother one day have wrapped the fallen cord in its cloth and preserved it as a keepsake, or laid it aside only to rediscover it after the death of her baby, triggering a flood of emotion?

Could the keeping of the cord have begun like this? Perhaps. Other customs suggest, though, that the umbilical cord might have been preserved for ritual or medicinal use. In Mie Prefecture, it was believed that a stillborn baby buried with its umbilical cord would receive nourishment and comfort and would not cry at night in its grave. In some areas, a critically ill infant or child would be given a medicinal drink prepared using the cord. In Saitama the same concoction was used to treat infants’ colds.

This symbol of life’s beginning was often linked with life’s end, as well. One custom was to place the birth-cords of a woman’s children into her grave. This would then prove to Enma, or Yama, the King of Hell, how many children she had borne.

It was not always the case, however, that the mother kept the cord. In some areas the heso-no-o was traditionally tossed at a crossroads or buried at the gate to the family home. In Kita-matsu’ura, Nagasaki Prefecture, part of the cord was wrapped in paper along with some baby hair and thrown into the ocean. In Okayama, reflecting the Japanese liking for the number three, when a person turned 33, their dried cord was returned — along with 33 yen or 330 yen.

There seem to be too many traditions to mention — and doubtless still others exist, unrecorded and preserved only in the memories of Japan’s elder generation. This country’s mountainous geography means that many communities once existed in relative isolation, creating a wealth of localized folklore. Although this makes it difficult to be certain about the origin of the Japanese attachment to umbilical cords, it means that you can hear stories of your own just by going and asking.