Sense of Smell
The sense of smell is closely allied with the sense of taste. The organs of the sense of smell are simple nerve-endings in papillae or pits. The substance to be smelled must come to the organs of smell as a gas or vapor. This example shows the smelling pits on the expanded terminal segments on the antenna of a leaf-eating beetle.
Winchell, Alexander Sketches of Creation (New York, NY: Harper & Brothers, 1870)