The layer of cork thus formed cuts out the dead debris and serves to, protect the uninjured cells below.
Each cone cuts out an area on the surface equally inclined to the cone axis.
When they have been reduced to the correct thickness they are examined by the " tryer," who cuts out one or two blanks from each fillet with a hand machine and weighs them on a delicate balance.
If one cuts out by a diaphragm in the back focal plane of the objective all diffraction spectra except the principal maximum, one sees in the image a field divided into two halves, which show with different clearness, but no banding.
The ear is surrounded by the ear cups which form an almost airtight seal and cuts out disturbing outside noise.
