The procerebral lobes also give origin to the nerves to the ocelli (_no_). [Illustration: FIG. 250.—Transverse section through the brain of the locust (Œdipoda and Caloptenus): _c′_, lower part of the wall of _c_, calyx;—_st_, stalk of the same; _bpcl_, bridge of the protocerebral lobes; _mo_, nerve of median ocellus; _ch_, transverse fascia of the optico-olfactory chiasma; _fcb_, fibrous region of the central body; _lcb_, tubercle of the central body; _fch_, descending fascia of the optico-olfactory chiasma; _choo_, superior fascia of the optico-olfactory chiasma; _pt_, protocerebral lobes; _ld_, dorsal lobe of the deutocerebrum; _lt_, tritocerebral lobe; _gcld_, _gc_, ganglion cells.—After Viallanes. ] =The mushroom or stalked bodies.=—These remarkable organs were first discovered by Dujardin, who compared them to mushrooms, and observed that they were more highly developed in ants, wasps, and bees than in the lower insects, and thus inferred that the higher intelligence of these insects was in direct relation to the development of these bodies. We will call them the _mushroom bodies_. These two bodies consist of a rounded lobular mass (the trabecula) of the procerebral lobe, from which arises a double stalk (Fig. 253), the larger called the _cauliculus_, the smaller the _peduncle_ (or pedicel); these support the cap or _calyx_. The calices of the bee were compared by Dujardin to a pair of disks on each side of the brain as seen from above, “each disk being folded together and bent downwards before and behind, its border being thickened, and the inner portion radiated.” In the locust there are but two divisions of the calyx; in the cockroach, ants, wasps, and bees, four. The shape and relation of the mushroom bodies are represented in Figs. 252 and 253. The bodies are connected by commissural fibres, and are connected with the optic ganglion of the same side, and with the central body; while they are connected with the antennal lobes by the optico-olfactory chiasma. [Illustration: FIG. 251.—Sagittal section through the brain of the locust: _l. oc. n_, lateral ocellus nerve; _a. t_, anterior tubercle of the mushroom body; _i. t_, internal tubercle of the mushroom body; _c. l_, cerebral lobes; _l. l_, lateral lobe of the middle protocerebrum; _com_, commissural cord; _c. mol_, central mass of the olfactory lobe; _ac. an. l_, fibres uniting the median lobe of the middle protocerebrum with dorsal lobes of the deutocerebrum; _gc. trit. l_, ganglionated cortex of the tritocerebral lobe; _c. an. l_, cortex of antennal (olfactory) lobe; _lab. fr_, labrofrontal nerve; _oe. com_, œsophageal commissure; _tr. com_, transverse commissure of œsophageal ring; other letters as in Fig. 250.—After Viallanes. ] The stalked bodies are enveloped by the cortical layers of ganglion-cells, those filling the hollow of the calyx having little or no protoplasm around the nucleus.