In Oxen of the Sun Stephen imagines all of humankind "linked up" with its first mother, Eve, "by successive anastomosis of navelcords." An anastomosis, in medicine, is a connection between adjacent tubular structures, whether natural (e.g., capillaries), accidental (e.g., fistulas), or surgical (e.g., gastric bypass). In Stephen's imagination such connections can be both interpersonal and infinite. The umbilicus connects the vascular network of the child to the vascular network of its mother, another umbilicus connected that mother to her mother, and so on, with the logical result that all of us are still bathed in the first woman's blood.

JH 2018

Two types of naturally occurring anastomosis between arteries and veins. Source:

Four types of surgically created anastomosis between arteries and veins. Source:

The two anastomotic organs, umbilicus and placenta, connecting the fetus to its maternal host. Source: