Well, I think the study was published in 1996, but the structure and
function of the stinger "assembly" had been studied before, of course.  It
doesn't seem to be primarily capillary-action based.  The barbed lancets (2)
alternately extend and retract, digging the stinger in deeper.  When they
extend, a bell-shaped diaphragm pulls venom from the sack and simultaneously
pushes venom from the pumping chamber into the hollow channel.  I haven't
found any references to actually trying to push venom through by squeezing
the sack... but I bet somebody has measured how much, if any, you can expel
that way.

Best image I found of the parts:
                  http://www.beekeeping.com/articles/us/bee_stings.htm

Best description I found of how it works:

http://website.lineone.net/~dave.cushman/stingstructure.html

On Sat, Oct 1, 2011 at 1:13 PM, Chris Slade <[log in to unmask]> wrote:

> Huh!  How about that?!  It turns out that the injection system is
> based upon valve action, not venom sack pumping -- there are no
> uscles around the sack.
> Is this new?  I was told 30 years ago that the sting does not act like a
> hypodermic syringe but that the venom flows along the grooves by capillary
> action.
> Chris
>

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