Which way does a chicken lay an egg? Little end first - and ease into it? Or big end first and finish with a relief? In the hopes of avoiding wars on the level of Blefuscud vs Lilliput, and despite no real help from the internet, I can give you a definitive answer - with a twist!
Last weekend I had a lucky purchase of seven boxes of magic lantern slides, "mostly anatomical" from Willingham Auctions. I went along to inspect them in person, and left my lucky bid, to then collect, photograph and hoard like a leprechaun. Some of the boxes, and slides are labelled J. A. Fairfax Fozzard (what a wonderful name!), who worked at the Department of Anatomy at Cambridge University. Amongst his many achievements (including moving away from Yorkshire and his Honorary FRPS), he took some revealing X-ray images of an eggs forming inside chickens. These boxes of magic lantern slides contain excellent copies of these pictures which I made into this summary.
Do you see what I see? At 23 hours 30 minutes - it looks ready to come out small end first. But then at 25 hours 30 minutes - it looks ready to come out big end first.
So I wondered. Did Mr. J. A. Fairfax-Fozzard grab whichever chicken was available and take an X-ray? And one chicken may lay her eggs big end first, others lay them small end first. Or even lay them randomly? And if the latter, then this could be one chicken, but photographed laying a series of eggs rather than just one.
I have spent all week fruitlessly searching for the answer. (Though I did learn about the marvellous chalazae - counter-rotated twisted strands of protein stretching from the big and small ends of the egg to hold the yolk in the centre.)
Unexpectedly, I found the answer to the egg laying direction in Mr. J. A. Fairfax Fozzard's obituary (written by the marvellous Leonard Frank Hansley Beard, another FRPS as well as a FIBP, who worked at Addenbrooke's Hospital in Cambridge).
The option I only briefly considered, and had rejected as preposterous, was that these images are of one chicken laying one egg. Summarising the seminal paper Passage of a hen's egg through the oviduct*: "the egg does a dramatic 180 degree about-turn shortly before it is laid".
That's gotta hurt!
But the answer to the original question is that it comes out big end first, after a twist, and presumably all the better to balance when dropping out. (And, to me, chickens are telling us to eat the egg from the little end first - take that, Blufescud!)
I also now imagine that Mr. J. A. Fairfax-Fozzard designed a chicken holster, transparent to X-rays, but worn throughout that long day (and night) by the chicken to make getting his photos punctually a bit easier. I suppose it must have looked like fish-net stockings and suspenders with a leather holster shaped like lederhosen. (I have no evidence for this, but would welcome artist impressions of what you are now imagining.)
WHY does the egg do a dramatic 180 degree about-turn shortly before it is laid? Probably because evolution can be a sadistic bitch, especially to the girls (ask a hyena giving birth). But again, answers welcome on a postcard/in the comments section.
We will hear more from Mr. J. A. Fairfax Fozzard's wonderous slides, that deserve their place in history.
*Unfortunately I haven't been able to read the original paper as it is trapped on the internet behind paywalls. But I have found this extract, though the images lose their wonderful clarity in this reproduction.