IF THE human race consisted of females alone, the connection between the moon and the womb might have resulted in some insights acted out through hiding from light, covering the menstruant with brush and other elementals of the seclusion rite, but human culture would not have burst forth with the language, tools, and structures it has today. Fortunately, our ancestress had another piece of the puzzle to work with besides blood, water, and the moon; she had a mate, and sons, and as they did not menstruate, they did not have a direct connection to the moon's path and to the human comprehension of cycles. The necessity of women to teach their special knowledge, not only to their daughters, but to their sons --- for whom it would always be a mystery outside themselves --- and the methods the males devised to display their comprehension, are what has created human culture over the millennia.
The Great Abyss that ancestor women stepped across repeatedly to get us where we are today fills me with awe; yet the Abyss for men is even greater. For if the Abyss from animal mind to human mind was a great yawning cavern for females, for males it was infinitely broader and more mysterious. They had to find ways to comprehend and identify with ideas contained in rites that were completely based in blood cycles, physiological states their bodies did not experience. They had to understand the complete abstraction of women's menstruation before they could learn the measurements it made possible. [p. 43]
The men achieved this comprehension, which had to be physical, in a number of ways. While women bonded through entrainment with their common flow of blood, including birth blood, and created an increasing complex of rites, men bonded and created rites entirely their own, yet centered on exactly the same subject. Probably the most obvious and easiest crossover rite was a translation of menstruation into bloodletting. That all blood is menstrual blood is well-illustrated by practices of men in which they deliberately produce blood from their own bodies.
"Parallel menstrual rites" include boys' puberty ceremonies involving bloodletting, special instruction by their elders, imitation of menstrual taboos, and induced visionary or hallucinatory states. According to ethnographical accounts of California Indian tribes, especially of last century, boys had far fewer and less elaborate puberty rites than girls, but the male rites, though sparser, instruct us about how information crosses between the genders.
Men undertook menstrual abstractions in the most physical manner possible. They bled deliberately in formal rites whose parameters were identical, though not as elaborate, as those surrounding their sisters, mothers, and wives. Quite literally, boys and men entrained their own blood with the flow of their female relatives, weaving themselves into the metaformic web of human mind. Mythology says they also induced bleeding in women's bodies, and this, too, gave them identification with menstrual power and access to human mind. It also gave them the peculiar human quality of blood power through premeditated murder.
In the beginning the men were animals and lived alone; women lived together in the sky and were happy. Every night the women descended from the sky on a long cord, eating the food with both of their "mouths." Then one day the men threw stones at the women, knocking out their teeth so that they bled from both "mouths." This created menstruation. [p. 44]
This story from northern Argentina suggests an ancient sacrificial rite that led to the instruction and identification of men with the sky knowledge imparted by menstruation. Because the women bled from their mouths (equated in the story with their vaginas) as a result of the men's action, the men had a direct, physical part in the blood power rite. Menstruation was then a public event, conscious to both sexes, and therefore "created" by the men.
The next logical step in creation of consciousness through identification with blood was for men to knock out a boy's tooth at puberty in order to produce a male "bleeding mouth": "Among the Australian tribes it was a common practice to knock out one or more of a boy's front teeth at those ceremonies of initiation to which every male member had to submit before he could enjoy the rights and privileges of a full grown man … In some of the tribes about the river Darling, in New South Wales, the extracted tooth was placed under the bark of a tree near a river or water‑hole; if the bark grew over the tooth, or if the tooth fell into the water, all was well; but if it were exposed and the ants ran over it, the natives believed that the boy would suffer from a disease of the mouth." In other cases, all the men in turn kept care of the boy's tooth, before finally passing it to the boy's father.
The most extreme and the most informative parallel to menstruation is subcision. An operation on the penis that is unabashedly imitative of menstruation, subcision reshapes the penis to resemble a vulva by splitting it along its length, with the scar being periodically reopened so that blood can drip down over the man's lower body.
The idea is that when the split penis is held upright against the man's abdomen it resembles a menstruating vagina. This extreme operation, or subcision, was reportedly done in New Guinea, Australia, the Philippines, and Africa. In some places in New Guinea, the word for the cut penis is the same as a word meaning 'the one with the vulva'; in others the blood that is periodically caused to flow from the wound is called 'man's menstruation.' Another people say that the blood flowing from the wound is no longer the man's blood:
Since it has been sung over and made strong, it is the same as the menstrual blood of 'the old Wawilak women' [the ancestral sister creators who first recognized the synchronization of menstrual with lochial, or birth, blood].
At least some of the men's subcision rites in Australia were timed with the new moon, according to Chris Knight, meaning that men learned how to synchronize with the lunar cycle very directly by imitating menstrual synchronization with their own blood.
Circumcision is a milder form of parallel menstruation, performed by peoples who oftentimes no longer give it that connotation. In Africa in particular, circumcision is common. The Dogon, a farming people, use circumcision to parallel the pain of childbirth, as a method of balancing the experience of the sexes. They say that circumcision extracts the "female" (the round circle of skin) from the man, and that excision of the clitoris extracts the "male," from the woman. 
Circumcision is a family rite among Hebrews. The bris ceremony performed eight days after birth marks the passage of a boy into the family. Since Jewish families are matrilineal in the sense that orthodox Jewish identity passes along the female lineage, bris seems a method of incorporating the male baby into a female "blood" lineage.
The men of the Caraja and Javahe tribes along the Amazon River go every so often to the sandy beach along the water in order to bleed themselves. One of their number, usually a medicine man, uses a piece of hard bottle gourd embedded with sharp fish teeth as a cutting instrument. He slices long cuts across the backs of the men's thighs, so that a plentiful spurt of blood ensures a rich red stream down the backs of their legs into the sand. Then the long wound is washed in the river, and the young men rub their cuts with green‑pepper pods and leaves. Scars last through life; the men say they feel much better after they have been bled. Women do not do this rite, as a rule. It is a men's ritual, and women do not attend it. [p. 46]
Secret society shamans of the Miwok and other peoples of California initiated boys in a four‑day puberty ritual of ordeals and instruction during the course of which the boys were made to bleed from their navels. "During initiation a young boy was tossed back and forth over the fire, treated roughly, had burning coals placed on his hands or neck, and finally was thrown out the smoke hole. He lay belly down over the hole and a small arrow was shot into his navel. He was then rolled down and his parents bathed him in cold water. At the end of the initiation period, a general feast was held in the dance house. "
Boys' rites treated the blood they were shedding with some of the same taboos as had developed in the rites of menstruation. While the initiate was being bled in some tribes, neither his body nor his blood were allowed to touch the ground: "In some Australian tribes boys who are being circumcised are laid on a platform, formed by the living bodies of the tribesmen; and when a boy's tooth is knocked out as an initiatory ceremony, he is seated on the shoulders of a man, on whose breast the blood flows and may not be wiped away. "
Besides the treatment of the blood, other rites of menstrual seclusion passed over to boys and men at puberty: "Restrictions and taboos like those laid on menstruant and lying‑in women are imposed … on lads at the initiatory rites which celebrate the attainment of puberty; hence we may infer that at such times young men are supposed to be in a state like that of women in menstruation and in childbed. Thus, among the Creek Indians a lad at initiation had to abstain for twelve moons from picking his ears or scratching his head with his fingers; he had to use a small stick for these purposes."
Boys of the Atsugewi in California "underwent a ceremony at puberty (when their voices changed). They were said to be having [p. 47]
… 'monthlies' and wore skunk‑brush belts. The father or another industrious man lectured the boy, pierced his ears, whipped him with a bow string or coyote tail, and sent him on a power quest." 
In these very specific ways, men were incorporated into the metaformic mind. In addition to parallel menstruation, men have also practiced parallel birth, or couvade, keeping rigid taboos while women give birth, even experiencing sympathetic birth pains. Ancient Greeks thought the male ejaculation coagulated the blood in the womb in some way, causing pregnancy. The Tiwi of Melville Island, as well as other peoples, incorporated the male into creation in their belief that sexual intercourse causes menarche. (I am reminded, here, of the slang for penis, "prick," and also of the widespread male obsession with breaking a virgin's hymen, with much fuss about the ensuing show of blood, still a practice today, for instance, in some Middle Eastern and African villages.)
In modern materialist societies, men and boys often bond through some show of bloodletting, a fistfight, say, that ends in friendship. In parts of Germany, young men have scarring societies, using swordfights to draw blood from each other, and taking pride in the number or length of their scars.
Males also participated in menarchal ceremonies, especially in the public
feast that so often followed the emergence of the menstruant from her first
seclusion. Navajo men help make the round pit to bake the ceremonial cake
of Kinaalda; they bring the hot water for the mix and help pour the batter. In
many North American tribes, men brought deer‑hoof rattles and other
presents for the secluded maiden. Among the Tucuna of the Amazon River region,
young unmarried men play very special roles in menarche; they have their
own hut, in which they make masks, and which women cannot enter on pain of
death. The masks are of spirits, especially evil spirits, spirits of particular
powers detected in the forest around them. The masked men are called on by
mothers to reach into the house
walls to frighten younger children who might otherwise wander the dangerous forest of the Amazon basin too heedlessly; the masked figures can be said to scare them into consciousness. The men wear their masks to the public feast honoring the menstruant, who emerges from weeks of seclusion on the third day of the festival. Shortly before she does, the masked men grab the seclusion hut and shake it as part of their duties of enacting fearsome spirits. Their masks are of serpents, parrots, the winds, monkeys, and imaginative motifs. In other areas, young men are sometimes given the role of flailing the female initiates as they run a race; the harder times are, the harder the blow of the flail. I remember how my older brother teased and tormented me with the cruel zeal of one long‑trained for the task of keeping women and children awake and alert, as though fulfilling, without consciousness or structure, his assigned male role to shake us and rattle us.
For the male, blood was something he could acquire primarily through inflicting or enduring a wound. To become an adult, he was expected to undertake frightening, exhilarating, painful, and bloody tasks. Not that women didn't cut with flint, but cutting or piercing to draw blood was the primary method by which males entered the metaformic mind, and therefore something they came to imagine as "theirs."
Tribal people of North America said that male and female blood powers had to be kept separate because they would interfere with each other, so a menstruant did not eat with men, especially hunters, gamblers, and shamans, because it would destroy their “power." Through careful separation, and through parallel menstrual rites, men as well as women had access to the metaform, and to the creative power of blood.
In English, man (pronounced "mon") was the word for female and wer the word for male only a few centuries ago. Man comes from Sanskrit, meaning "moon," so man is cognate with menstruation [p. 49]
and mind, and wer with virility, strength, virtue, and cleanness. Wer remains in the language in the word "werewolf," a particularly bloodthirsty predator in European folktales.
According to the OED, the word woman is made of two old words, man (moon) and wo, which was originally wyfe. This word did not mean "married female," however. From its pronunciation, "Weef," and its meaning, "maker" or "producer," it more likely meant "weaver," in the sense of "weaving the fabric of culture," or perhaps "gatherer." (A similar term is "spinster"). In sixteenth-century England, all manner of country "weefs" came to market to sell their wares and products: an ale‑weef brewed and sold ale, a strawberry‑weef sold her truck‑farm fruits, an oyster‑weef sold her sea fruits, and so on. The derogatory slang word "fishwife" remains as a fragment of the earlier usage.
To do some etymological speculation, a "weef‑man" was a menstrual "moon weaver." Over the three or four centuries since this time, "weef‑man" dropped its 'f' and became "wee‑mon," as you can still hear in some American folk accents, and then it was slurred into the more contemporary pronunciation "wimmin." "Weef" changed in pronunciation to "wife," a common progression in some English dialects. And as females became economically dependent on males in paternalist marriage, the sense of "wife" as an independent marketwoman vanished.
The mate warrior tradition acquired another use of "mon," in the word "weapon." The "weap" part of the word means to seep fluids, as in the modern spelling "weep." Wounds "weep" blood, brought about by the "weap‑mon," the moon-human who acquires blood by cutting with a flint or other tool. "Man" was applied to both genders until the seventeenth century, and this earliest man, menstrual man, stands behind "weap" man and "weef" man alike. In the beginning was blood and the moon, with the irregular rhythm of metaform passing between them. [p. 50]