ANATOMY OF THE NERVE CENTRES. 461 
pharyngeal, maxillary and antennal nerves. The pyramidal 
ganglion consists of large cells closely packed together, and 
there are several gigantic nerve cells in the gray matter sur- 
rounding the cesophagus, resembling the largest stellate cells 
of the anterior cornua of the spinal cord of Vertebrates. 
The Corpora Fungiformia are two in number, on each side of 
the brain, an external and an internal corpus fungiforme. These 
bodies may be described as cup-shaped prolongations of the 
medulla, filled by and imbedded in the cellular cortex on the 
posterior surface of the brain. 
Each corpus fungiforme is said to consist of a calix, filled by 
and covered with small nerve cells. 
Each calix is funnel-shaped, supported bya stalk or peduncle 
at its narrow extremity. The peduncles of the internal and 
external calix perforate the medullary core, or hemisphere of the 
mesocerebron, and unite with each other, forming a thick bundle 
of parallel fibres; this bundle is termed the trabecula. The 
trabecula crosses the internal cavity to the anterior surface of 
the brain, and terminates in a rounded caput in the lower part of 
the frontal lobe. From the caput two short thick processes are 
given off at right angles to each other, one ascends through 
the frontal lobe, the anterior tubercle; the other takes a nearly 
horizontal course to the medium line, the internal tubercle. In 
the Orthoptera the trabecule are far more massive than in the 
Diptera or Hymenoptera (compare Fig. 54). 
The Calices.—Each calix is a hollow cone of very fine fibres, 
which radiate from the apex of the cone, where they form the 
peduncle of the corpus fungiforme (Hinterast, Flégel; Pilzstiel, 
Dietl); these fibres extend from the calix into the gray sub- 
stance; and the small round cells of the cortex are frequently 
seen in sections, arranged in radial lines corresponding to the 
course of these fine fibres (Pl. XXXIII., Fig. 2). The calix 
itself is formed by the union of these fibres in their course to 
the trabecula. It is not circular in transverse sections, but is 
seen to be corrugated irregularly in a longitudinal direction. 
Historical and Comparative Anatomy of the Corpora fungiformia. 
Dujardin first discovered the Calices in Bees (Apis and 
