According to Norse myth, Ymir, while sleeping, is giving life to numerous children, and doing this solo. It aligns well with the "twin" meaning of his name roots. It seems Ymir contains both twins, including Yami's aspect of Life.

By the way, Auðumbla licks ice blocks and at some point reveals Búri out of the Ice, the ancestor of the Æsir gods. This story is the first time when a specific time is mentioned: Búri gradually appears from the ice over three days. It indirectly supports our version of the connection between Ymir and the beginning of time, as suggested by comparison with Saturn.

These two independent branches of Gods and Giants are represented by the upper and lower hands of the rune Perthro:

The name and meaning of the Perthro rune are unclear from Norse sources. One version is a "pear tree" or more generally a "fruit tree" (e.g., apple tree). From a Runic Alchemical point of view, the tree interpretation is also supported by:

• Sharing the trunk and top bar with the other two tree runes Eihwaz and Berkana.
• Sharing two bars, top and bottom, with Berkana.
• Vertical symmetry representing crown and roots. All tree runes have a sort of vertical symmetry, which is mirrored in the case of Eihwaz.

Another version is a sort of wooden board game or dice.

Let's look at all the transitions happening in this rune:

Water comes to the Air and bounces back to the Water. The same for the Fire traveling to the Earth and returning. But in both cases, they are not the same as they were on departure. The Water acquires something from the Air and the Fire from the Earth. I believe this is how worlds of Water and Fire become inhabited—they now contain some shapes. Surtr, the giant of Fire, is born by the dreaming Ymir, so Fire has its "avatar." Búri, the early god of the Water, is shaped by Auðumbla and starts the line of all the gods.

Overall, based on the above, we can describe the rune Perthro as fruits, offspring, cause-effect, side-effect, aspect, story, and fate.