72 ANATOMY OF THE RABBIT. 
slender funnel-like structure, the infundibulum, the tip of the 
latter being in contact with the pituitary body or hypophysis and 
its base connected with a small grey elevation, the tuber cinereum. 

Fic. 39. Plan of the divisions of the vertebrate brain: A, embryonic; B, 
adult, projection from dorsal surface; C, adult, sagittal section. The contour 
of the mammalian brain is indicated by broken lines. 2 
Primary divisions—PR, prosencephalon; T, telencephalon; DI, diencep- 
halon; MS, mesencephalon; RH, rhombencephalon; MT, metencephalon; 
MY, myelencephalon; S, spinal cord. 
a.c., cerebral aqueduct; b.o., olfactory bulb; c., corpora quadrigemina; 
cb., cerebellum; c.m., mamillary body; c.o., optic chiasma; c.p., pineal body; 
f.i., interventricular foramen; h., hypophysis; h.c., cerebral hemisphere; in., 
infundibulum; |.t., lamina terminalis; p., pons; pl., chorioid plexus of third 
ventricle; p.c., cerebral peduncle; t., thalamus, also indicates position of massa 
intermedia; v.l., lateral ventricle; v.m.p., posterior medullary velum; v.q., 
fourth ventricle. 

Its cavity is the recessus infundibuli. Immediately in front of 
the infundibulum the ventral portions of the optic tracts join to 
form the optic chiasma, and immediately behind it the floor is 
ht 
