PLATE XV. 
Fig. 1. — Frontal section No. 10, through the head of second or last pupal stage of C. spre- 
tus, passing through the middle of the brain, the optic ganglion, and eyes, and 
cutting across the oesophagus. Drawn in order to show the relation of tho 
brain to the eyes and the exterior of llic head ; magnified 1!0 diameters. In 
the brain the right mushroom body is seen, while the optic and antenual 
lobes are not so well marked. The central body (centr. b.) is cut through 
near the middle; below are the trabecular (trab.), nextto the commissural 
lobes, two trachea; (tr. ) or air-tubes passing near the brain. The commissure 
to tho suboesophageal ganglion is drawn on the right side, passing down 
the oesophagus. In the eye the cornea, the respective portions composed 
of rods and cones, the black retina, the stratum of optic nervules, and the 
optic ganglion and optic nerve passing off from the optic lobe are all well 
marked. 
PlG. 2. — Section through the brain and eyes of the same second pupa of C. spretus, 
passing through the anterior part of the calices, but not through the cen- 
tral body. The section is oblique and does not well represent the right 
side. 
Fig. 3. — Calyx of the section represented by Fig. 2 ; magnified 225 diameters. It is 
composed of granulated nerve substance with a few fibers, the continua- 
tion of those of the stalk, and with a few ganglion cells. 
FiG. 4. — Section through the back of brain of the adult Locusta Carolina, passing he- 
hind the mushroom body, showing the oesophageal commissures, the anten- 
ual lobes, and the bundle of nerve-fibers crossing to the right hemisphere. 
The left calyx is cut through, the microtome -razor passing behind and not 
grazing the right mushroom body. The distribution of the large (Z. g. c.) 
and small ganglion cells (sw. g. c.) is well seen in this section. It will be 
seen that the brain of Locusta Carolina does not differ in any respect from 
that of Caloptenus spretus, so far as the sections show. 
