~ 
George E. Shambaugh 257 
represents a marked distortion is quite evident from the study of: prepa- 
rations such as I have shown in my drawings where the separate lamella 
can be traced running their entire course without so much as a fold or 
ruffle. The type of resonator which Kishi seems to have in mind for the 
membrana tectoria is that of a series of taut strings attached at either 
end. This is not in keeping with the anatomical facts as brought out in 
this paper. 
ABBREVIATIONS USED. 
M.t. =Membrana tectoria. 
M. b. = Membrana basilaris. 
L.v. =Labium vestibulare. 
L.t. =Labium tympanicum. 
L.s. =Ligamentum spirale. 
C.l.s. =Crista ligamenti spiralis. 
M. R. =Membrana Reissneri. 
P.S. = Prominentia spiralis. 
S.v. =Stria vascularis. 
S. H. =Streifen of Hensen. 
EXPLANATION OF PLATES. 
PAATE I. 
Fic. 1. Section from lower end of basal coil showing membrana basilaris 
too thick to be capable of vibrating. 
Fics. 2, 6. Section from lower end of basal coil showing complete ab- 
sence of a membrana basilaris. The organ of Corti rests on the firm struc- 
ture of the crista of the spiral ligament which is attached directly to the 
labium tympanicum. 
9 
Fic. 3. Section similar to Fig. 2. A solid bony plate extending across 
from the outer wall of the cochlea to join the lamina spiralis ossea. 
Fig. 4. Membrana tectoria attached to the organ of Corti. Streifen of 
Hensen partially withdrawn from its normal attachment to the supporting 
cells just internal to the inner row of hair cells. These supporting cells 
have also been somewhat pulled out. The preparation shows the inner hair 
cell detached from the membrana tectoria. The outer hair cells are still 
attached to the membrana tectoria. 
Fic. 5. Membrana tectoria partly withdrawn from the organ of Corti. 
The Streifen of Hensen detached from its normal support as shown in Fig. 4. 
Inner hair cell free from membrana tectoria, the outer hair cells still clinging. 
PeAres Die 
Fics. 6, 7, 8, 9, 10. A series of sections from a single labyrinth drawn to 
scale showing variation in size of membrana tectoria from the beginning of 
basal coil to apex of cochlea. 
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