THE EAR AND HEARING. 
213 
moderately hard, slialy, highly micaceous bed, which is easily 
identified as “ J ” of the typical section; it contains: 
Protocardium truncation , Pleuroimja costata , Limea acuticosta, 
and Fucoids (abundant.) Below this is a reddish, micaceous, 
sandy bed, like bed “ K,” everywhere in the district. A little 
further from Daventry, just over the ridge of the hill, another 
hard bed is found in the bank; it is slialy, weathers rather 
white, contains very little mica, and much more resembles 
“ F ” than “ H.” No fossils were obtained, although parts 
of it seemed to be made up of comminuted shell. Apparently 
bed “ H ” ceases to exist as a distinct hard bed in this 
neighbourhood, for I have not found it in anv section further 
north. 
Several Middle Lias beds may be seen on the railway near 
to Watford Lodge, a description of which will appear 
later on. 
I believe the junction of the Middle and Lower Lias may 
be seen in a brook near to Elkington, but if so the bottom 
bed is absent. This is not surprising, because the whole of 
the Middle Lias is very much attenuated here, the rock-bed 
itself being very indifferently represented. 
'o be continued.) 
THE EAB AND HEARING. 
BY W. J. ABEL, B.A., F.R.M.S. 
(Continued from page 201.) 
Upon the surface of the scala media lie several 
important structures.—1. On the side towards the tympanic 
scala is the very elastic Basilar Membrane upon which 
stand about 3,000 club-shaped fibres arranged in pairs form¬ 
ing arches. These fibres are called the Rods of Corti, and 
are thought to contain at least oue nerve filament each.—2. 
Over these rods is the Membrane of Corti containing numerous 
cells of various shapes, and 3. On the partition separating 
the scala media from the scala vestibuli is the membrane of 
Reissner. Wandt believes that different tones affect different 
parts of the nerve of hearing thus disposed, and that, as 
elastic bodies respond each to some particular tone, and 
remain quiescent when other tones are sounded, so the 
elastic tootli-sliaped pairs of rods of Corti, together with 
the superposed laminae, are divided into groups responsive only 
to the stimuli of given notes, so that every fraction of a 
tone which a well-trained ear is capable of recognising is 
