PLATE XL 
Fig. 1. — Section 19 ( X i A.), passing through the back of the brain, showing the pos- 
terior edge of the oalices and antennal lobes and oesophageal commissural 
nerves and optio nerve, tr., small trache*. 
Fio. 2. — Section 20, passing through the back of the brain, showing the relation of 
the optic nerve to the optic ganglion and eye ; the cornea, cones, rods, and 
retina of the eye are 6hown ; X \ A. eup. «., superior, m. «., median, and 
inf. «., inferior commissural nerves connecting the hemispheres. 
Fig. 3. — Enlarged view of upper part of the stalk and calyx, and the ganglion cells 
surrounding and filling the latter; X 225 diameters. 3 a, b, c, d, different 
ganglion cells seen from different directions, 3 c showing the large nucleus 
lilled with coarse granules, but showing no nucleolus ; one, however, is seen 
in Fig. 3 b. ncl. ; X 725 diameters. 
Fig. 4. — Longitudinal section of iho brain and suboesophageal ganglion, ma<;ni(ied 
50 diameters, showing the relations between the two, and of the origin of 
the oesophageal commissure from the upper side of each ganglion, i. e. t 
from the back of the brain and the upper side of the suboesophageal gan- 
glion. 
Fig. 5. — Enlarged view (X i B) of the suboesophageal ganglion of Fig. 6, PI. X, show- 
ing the origin of the commissure to the first, thoracic ganglion, and on the 
under side the three lobes (mandibular, maxillary, and labial), whence the 
nerves are sent to the mouth-appendages, mand. I., mandibular lobe; 
max. I., maxillary, and max. I'., 2d maxillary or labial lobe; com., commis- 
sure to suboesophageal ganglion. 
