Thank you, Harriet and David -- but I have two different answers now !
Harriet: could you please give details on why you think that the "gelatinous
mass" is the TM? As you know, that verdict is hard to swallow; von Bekesy
knew the TM well.
David: fairly ingenious! Agar and gelatin are even mentioned twice on that
page 475. The helicotrema was closed with such a mixture, and after
conclusion of the measurements at the apex, the scala tympani was
closed again with agar and gelatin. With "cochlear lumen", Bekesy means
"cochlear channel", I believe. But I do not understand that page 475
completely. Can that gelatin get into the cochlear duct ?
It would be nice if we could now clear up this gelatinous problem.
I asked the List about it a few years ago already, I believe, but
did not get answers then.
The problem is important to me in connection with Bekesy's
Fig. 11-73 (BM stiffness).
Datum: 19.03.2010 17:00
Betreff: Re: A question on Békésy.
The viscosity of endolymph is similar to water. The "gelatinous mass" is
probably the agar/gelatin mixture mention earlier on the same page.
On Fri, Mar 19, 2010 at 9:20 AM, reinifrosch@xxxxxxxxxx <
> Dear colleagues,
> At the bottom of page 475 of his book "Experiments in Hearing",
> McGraw-Hill, New York, von Békésy (1960) has written:
> "[...] It was further established that the gelatinous mass in the
> cochlear duct increased the rigidity of the partition, especially
> near the helicotrema. [...]"
> What is that "gelatinous mass"? I seem to remember that
> the viscosity of endolymph is about equal to that of water.
> A wild guess: "gelatinous mass" = tectorial membrane (??)
> Your (on- or off-line) suggestions would be very welcome,
> of course, even if you are not absolutely sure !
> Reinhart Frosch,
> Dr. phil. nat.,
> r. PSI and ETH Zurich,
> Sommerhaldenstr. 5B,
> CH-5200 Brugg.
> Phone: 0041 56 441 77 72.
> Mobile: 0041 79 754 30 32.
> E-mail: reinifrosch@xxxxxxxxxx .