378 The Brain of the Embryo and Young Locust. [May, 
A broad bundle of fibers is also seen on the right side, passing 
down from the upper side inside of the upper end of the pedun- 
cle, down outside and back of the central body, and is seen to en- 
ter the commissural lobe on its inner side, terminating at the point 
where the ascending fibers to the upper side of the trabecula 
originate. There is thus a direct communication between the 
upper part of the brain and the cesophageal commissure in the 
lower part. It appears, also, that three large nerves or bundles 
of fibers enter each commissural lobe from above. 
At the under side of the commissural lobes the cortical ganglion 
cells (some of them very large) appear to send their fibers into 
others to build up the mass of fibers enveloping the lobe. Flogel 
states that the opinion that the ganglionic cells in winged insects 
are in direct relation through the fibers with the organs of the 
body are unfortunately provisionally contradicted by his observa- 
tions. But here (seen in a portion of the commissural lobe not 
represented in Fig. 3 of Pl. 111), as in one or two other places, we 
think we have seen fibers from the cortical ganglion cells passing 
into and aiding in building up the nerves. Such a relation is very 
plain in the brain of the horseshoe crab, Limulus polyphemus. 
EXPLANATION OF PLATE IV. 
Fic. 1.—Enlarged view of brain and eye of C.spretus in the second pupal stage; 
xX %A. This view of the brain is taken from the same preparation (No. 10) 
as Fig. 1, Plate v. Cen¢r. b., the central body, showing the two series of cells 
in the lower division eat the two rows of unicellular bodies in the superior 
division; @. com. /., ce30 eal commissural Rite with the ball-like masses 
distinctly seen, though as preparation was stained only with picrocarmine 5 
@. com., cesophageal commissure ; off. one sil nervules ; retina, retina with 
rods si cones beyond, the cornea not shown. 
Fic. 2.—The central body of adult C. spretus, from section 17, showing the inferior 
and superior divisions, the cells in inferior division (if), and the two rows of 
unicellular bodies (ce. ce//. 6.) in the superior division (sz.). Magnified 225 
diameters. 
Fic, 3.—The central body of the second or last pupal state, from section No. 103 & 
cells in the fibrous septum between the lower and upper divisions of the central 
body, from section No. 11. \ 225 diameters 
Fic. 4.—Vertical section of the subcesophageal ganglion of the cockroach (B/atta 
peieubay showing the commissure on the le : 
Fic. 5.—A section farther behind, showing the ne of the ganglion (gang. ,) of the 
eng a seen separate from the commissure (com 
Fic. 6.—A section through the commissure just behind the ganglion © 
beta 
f the 
EXPLANATION OF PLATE V. F 
Fic. 1.—Frontal section No. 10, through the head of second or last pupal py . 
C. spretus, passing through the middle of the brain, the optic ganglion an oi aad 
