The connexion between the corpora striata, or chief remaining part of the hemispheres.
The midbrain is represented chiefly by the optic lobes, the cortex of which alone is homologous with the corpora quadragemina of the mammals.
It occurs in two different forms. In the Ratitae, except Rhea, it consists mainly of a right and left united half (corpora fibrosa), with a deep longitudinal furrow on the dorsal side, and much resembles the same organ in crocodiles and tortoises.
976; Siegert, " Corpora Amylacea," Arch.
23) relates how, according to Hermes, the spirits entered by invitation (spiritus invitatos), so that the images became bodies of the gods (corpora deorum).