B
Beefriendly
Guest
https://www.cardiff.ac.uk/news/view/37044-secrets-of-bee-honeycombs-revealed
“...........................”
That's the one. Well spotted. The reference for it is
http://rsif.royalsocietypublishing.org/content/10/86/20130299
And the interesting picture is this one, a new cell (round) and then 48 hours later (hexagon).