I recently read the Cullaka-Seṭṭhi-Jātaka in the Cowell-Chalmers edition for the first time. The two brothers in this tale, whose names Chalmers translates as “Great Wayman” and “Little Wayman,” are both born while their mother is still travelling back to her family’s household in order to give birth after her husband repeatedly delays the journey; hence the brothers’ names, because they were born “on the way.” Among a multitude of other fascinating themes at work in this tale, including its complex structures of repetition and recollection, I noted that this peculiarity of the brothers’ origin would instantly bring to mind the Bodhisatta’s own birth in the Lumbini Park while Māyā, the latter’s mother, was herself “on the way” back to her family household in Devadaha to give birth to him. Aside from binding the brothers’ story to the traditional story of the Buddha’s life at this one point, I am not well-versed enough either in the Vedic religion or in the ancient culture of the region more generally to derive any further meaning from this conjunction between the two stories. So my question for the group is: what significance - religious, familial, or literary - is there to be found in the fact that the mothers’ journeys to their respective family households remains incomplete in both cases, and their children are born effectively neither in their mother’s nor in their father’s house, but at a point somewhere in between? This piece of information would help me illuminate this detail in both stories. Thank you all in advance.
Thank for this wonderful tale of the Cullaka-Seṭṭhi-Jātaka. 
The mother’s journey is incomplete because of remorse and regret:
The children are always plaguing me. Are my parents going to eat us at sight?Come, let us shew the children their grandfather’s family.”
“Well, I don’t mind taking them there; but I really could not face your parents.”
A relevant quote is:
AN9.19:1.4: And so, having not fulfilled our duty, full of remorse and regret, we were reborn in a lesser realm.’
Yet their intention was the welfare of her children, the Wayman brothers. She wishes them well. A relevant quote might be:
AN4.171:6.4: There is a reincarnation where the intention of others is effective, not one’s own.
The story continues with a very (!) interesting exposition on dullards and compassion. 
@karl_lew Thanks very much for your reply.
Here you appear to be referring to the second round of delayed journeys to the mother’s ancestral home, rather than the first round during which her boys were born - the latter of these is the one I’m referring to in my original question. I can well understand the error, since structures of repetition and recollection, as well as the monastic practices of memorization and recitation, are much at play in this story.
I agree with you in a qualified way that the root of the delay in both rounds is (the husband’s) remorse and regret, though I don’t think it’s unreasonable to suspect that there is a good deal of plain old-fashioned shamefacedness and a desire to avoid awkwardness on his part as well - which is in fact creating considerably more awkwardness than it is trying to avoid. The situation is one of a man who knows that in the view of his in-laws, he is his daughter’s worst mistake. But this does not get at the primary issue of my question, which concerns what status the boys have as a result of not being born in the right house, as it were, and how this might resonate with the traditional account of the Buddha’s birth.
I am not clear on how you see rebirth playing a role here, at least insofar as you appear to be referring to the birth status of the mother. Can you clarify?
Without having read the particular Jataka you are referring to, I am pretty sure that this series can shed some light on your question.
The theme of being in-between two states is a recurring one in mythology in general and in some Jatakas in particular. Being suspended between heaven and earth is one variation of it; maybe being born between the father’s and the mother’s place another. I remember one Jataka (can’t tell which one exactly) where the child is literally suspended in the air, between heaven and earth, and this happens exactly between mother and father.
According to tradition the Buddha’s mother is giving birth while standing, so in this way too the child is suspended between heaven and earth.
Highly interesting talks!
@sabbamitta Your response is fantastically interesting and extremely helpful. I had unreflectively taken Buddha’s mother’s standing position as the usual position for birth in many traditional societies, but now that you draw my attention to it again, it unmistakably contributes to the in-between character of the Buddha’s birth in no uncertain terms. I have not gotten very far in my reading of the jātakas, but this is now a motif I will look for in other stories as well. Thank you many times over.
Historically, many societies punished runaway slaves with death preceded by cruel torture. Understanding this, his wife left in secret. She thought him a fool for not knowing how to safely assist her voyage. Yet on that solitary path to her family home, she gave birth on the way to her new baby. Giving birth alone is terrifying. Yet she managed. And in managing that singular challenge, she understood herself capable, no longer needing support from her parents for the birthing just experienced. And when her husband showed up, it was simply easier to return with him to exile. He had indeed found the courage to help her.
What is interesting to me is that all this happened yet again with the second baby. That is the mystery for me–did these two never plan anything? And the tale leaves it at that. For those in ignorance, craving endlessly leads to suffering. Perhaps that is the point of journeys not completed.
I was considering “spiritual rebirth”, rather than literal rebirth, in the sense that going forth is a rebirth into the spiritual life. Both Waymans became arahants, and both were set firmly on that path partly through the intentions of the grandparents as well as the parents.
In myth it is quite normal that things don’t always follow logical reason. Myth lives with obvious ambiguities, both in how a decision is made and in its take on moral judgement. Myth is not about logic and reason in the first place, but about trying to make sense of the highly ambiguous and contradictory world we are living in, and about creating narratives that support community building by having a common story about how things came to be the way they are.
I feel I am not really able to put this in the best words. I highly recommend the above mentioned series of talks. Buddhist mythology is a field not much explored yet, and if I wasn’t deeply involved in other projects I’d certainly dedicate it some of my time because it is so interesting!
Thank you for this, especially the clarification regarding rebirth - I thought perhaps you had something along those lines in mind, but didn’t want to put words in your mouth.
It’s quite true that we are left mystified as to why this heavily pregnant mother’s travails near the moment of labor have to be repeated a second time - but I would suggest that the motivation here is less psychological than literary. This whole story, not unlike the Joseph story in Genesis, is about repetitions, recitations, revisitings, remindings - and yes, rebirths. While it’s psychologically improbable that the husband makes the same mistake twice, the story is using his character as an instrument to make a bigger, richer point about Buddhist life, and this requires that the author violate our common-sense notions of human motivation. Simply put, I think he acts as he does because the symmetry of the story requires that he act that way.
@sabbamitta You underrate yourself here by wishing for better expression! I wish I had read your response before I responded to @karl_lew - it is both more concise and more general in its reach.
This is exactly what I was trying to express in my reply, but you enrich it considerably by suggesting that this is characteristic not just of literature (which inherits myth) but of myth in general.
What I say here is just what I learned from Bhante Sujato’s talks and what my somewhat week memory allows me to reproduce. 
Then I imagine I will have a very lively evening listening to these talks! Thank you again for this very rewarding conversation.
Most welcome! It’s just inspiring to see people interested in this mythology stuff!! 