570 
MR. BISHOP ON THE PHYSIOLOGY 
PLATE XXXI. 
The apparatus employed by Muller for making experiments on the human larynx. 
Fig. 3. N. Shaft or column for the attachment of the larynx. 
f. The forceps for compressing the larynx laterally. 
u. The bellows. 
v. The manometer connected with the tube u for estimating the tension 
of the air used in the experiments. 
M. O. Columns for the attachment of the pulleys x' and y'. 
x. A line by means of which the vocal cords are extended in the direc- 
tion of their length ; it passes over the pulley x’. 
y. A line passing over the pulley y’, by means of which the vocal cords 
may be relaxed and reduced to their minimum length, thus performing 
the office of the crico-thyroid muscle. 
2 . A line by means of which the vocal cords may be extended by draw- 
ing them downwards and forwards. 
Fig. 4. Apparatus for the lateral compression of the vocal cords in the production 
of the chest tones. 
a. A rod, to which the pincers f are attached, as a, fig. 3. 
b. Cross beam, to which the pincers being attached may, by means of 
the part c, be moved backwards and forwards, in order to adjust them 
to the proper position for the length of the vocal cords, as b , fig. 3. 
d. Screw for adjusting and securing the piece c. 
e. Screw for adjusting the rod a to the height required for compressing 
the vocal cords. 
f. The pincers. 
Fig. 5. Compressor, with graduated scale for measuring the position of the legs g, h. 
c. d. Screws for the approximation or separation of the legs g, h. 
e. Projection by means of which the position of the leg g is indicated on 
the scale. 
a b. The slab on which the compressor is fixed. It passes through the part 
b , represented in the apparatus, fig. 3, and may by these means be 
fixed in the required position. 
Fig. 6. Compressor, with two moveable legs, for making experiments on the human 
larynx for the chest voice. The parts c,d, to which the legs e,f are at- 
tached by hinges, move in joints on the part a b, and may be fixed by 
screws, g, h are small cords, by means of which the legs may be made to 
approach by the application of weights. 
Fig. 7- The glottis prepared for experiments. The arytenoid cartilages are firmly 
secured together behind the chink by means of a strong pin, and united by 
a ligature which serves to attach them securely to the column. The supe- 
