THE BRAIN OF THE LOCUST. 
233 
pears that there are four bundles of nerve-fibers passing out of each 
body. A bundle of transverse nerve-fibers (Fig. 2 t. c. n. and Fig. 3) 
passes along under the central body, directly through the middle of the 
trabecular, and anastomoses with the fibrous envelope of each trabecula. 
In front of this transverse intra-trabecular nerve is a small short ascend- 
ing bundle of fibers (Fig. 3, a. I. n.) which passes next to the pedicel, but 
does not apparently form a part of it, but anastomoses with the fibers 
on each side of the central body. Below, the fibres pass downward and 
outward to apparently connect with the fibrous envelope of the trabec- 
ula. Another short bundle passes out from the trabecula obliquely to- 
wards the central body and anastomoses with the fibrous envelope of 
the central body. 
Below, but in the same plane, is another transverse bundle of fibers 
(Fig. 3, I. t. «.), which is slightly curved and on the left side its fibers 
are distinctly seen to enter the trabecula. This lower intratrabecular 
nerve, as we may call it, connects with three vertical short nerves aris- 
ing from near the edge of the lower furrow between the hemispheres of 
the brain. Of these, the central one (centr. n.) is in the median line of 
the brain, and the lateral ones (lat. n.) are on each side. There would 
thus seem to be a direct double nervous communication between the two 
trabecular, and with the fibers surrounding the central body, and hence 
with the rest of the brain. This seems to be opposed to the statement of 
Newton that the trabecular, and the mushroom bodies in general, have no 
nervous connection with the rest of the brain. This section also clearly 
indicates the origin of the optic nerve, which passes behind the stalk of 
the mushroom body, and also the relation of the fibers of the stalk to 
the calices, as they appear to penetrate far into the interior of the body 
of each calyx. 
The double stalk (cauliculus and peduncle). — These names are applied 
to the larger and smaller divisions of the stalk of the "mushroom body." 
They are represented in the eighteenth section (Fig. 4) where the outer 
part of the stalk {cauliculus) supports the outer calyx, and the inner 
slenderer column of fibers supports or ends in the inner division of the 
calyx. These two bundles of fibers are somewhat curved, but as they 
do not appear in sections 16 and 19, must be less than of an inch 
thick. Their fibers are seen to penetrate deeply into the base of the 
calices, and thus to directly communicate with the fine granular sub- 
stance of the calices. 
The calices. — The cups of the mushroom bodies in the locust differ 
decidedly in form from those of the cockroach, and this part of the 
mushroom body is more variable in form in the different orders of insects 
than any of the other parts of the brain. It is nearly obsolete, or, as 
Flogel states, "not more than rudimentary" in hemipterous insects 
(notably Syromastes), and is less completely developed in many smaller 
moths, beetles, and flies, as well as Neuroptera (JEschna), according to 
Flogel, than in the larger moths, in the Orthoptera, and especially in the 
