part entering each lateral ventriele through the foramen of lonroe. In the third ventricle two vascular fringes hang down from the velum. These are the elioroid plexuses of the third ventricle. t he lateral ride, similar fringe are attached to the lateral margin of the velum. These are the eliornid plexuses of the lateral ventrieles.
The corpus finibriatum or ta•nia hippoeampi is the lateral edge of the posterior pillar of the fornix. It is a narrow white band lying just behind the ehoroid plexus of the lateral ventricle.
The fornix is an arch-shaped band of white fibres, running longitudinally, which bifurcates both anteriorly and posteriorly, forming the an terior and the posterior pillars of the fornix. The central portion or body of the fornix is tri angular in shape, its narrow anterior end being attached to the septum Incidum, its broad pos terior extremity being continuous with the cor pus callosmn. The anterior pillars curve down ward in the lateral walls of the ventricle and enter the corpora albieantia, from which they loess into the optic thalami. The posterior pillars of the fornix pass downward in the de scending horns of the lateral ventricle, their thin margin forming the already described corpora timbriata.
The hippoeampus major or corm' Anunonis, so called from its fancied resemblance to a ram's horn, is a long curved bodyconsisting of both gray matter and white matter which follows the curve of the floor of the middle horn of the lateral ventricle. It is formed by an extension inward of the dentate sulcus. The gray substance of the suleus forms an irregular ridge along the margin of the hippoeampus major, known as the fascia dentata. The lower end of the hippo campus major is marked by several rounded ele vations which from their resemblance to the paw of an animal arc known as the pes hippocampi. The hippocampus minor is a longitudinal emi nence in the floor of the posterior horn of the lateral ventricle. It is due to the extension inward of the calcarine suleus. The eminencia collateralis or pes accessorius is an eminence caused by the inward projection of the collateral fissure. It lies between the hippocampus major and hippocampus minor, and between the poste, riot and descending horns of the lateral ventricle.