STRUCTURE OF THE HIPPOCAMPUS MAJOR. 



173 



invagination of the cortex as the hippocampal fissure. According to Golgi and Sala 

 there is a second invagination into the fascia dentata : this must however be looked 

 upon as quite incomplete. 



The greater part of the grey matter of the hippocampus is occupied by several 

 rows of moderately large pyramidal cells (fig. 122, 5 ; fig. 124, 3) with long apical 

 processes, which lie embedded in a neuroglia-matrix, and confer upon this, especially 



7 



Fig. 124. SECTION ACROSS THE HIPPOCAMPUS MAJOR, DENTATE FISSURE, DENTATE FASCIA AND FIMBRIA 



(after Henle). 



Gh, part of the gyrus hippocampi or uncinate couvohition ; Fd, fascia dentata or dentate convolu- 

 tion ; between them is the dentate fissure ; Fi, fimbria, composed of longitudinal fibres here cut across ; 

 1, 2, medullary centre of the hippocampal gyrus prolonged around the hippocampus, H, as the so-called 

 alveus, into the fimbria ; 3, layer of large pyramidal cells ; 4, stratum radiatum ; 5, stratum laciuiosum ; 

 6, superficial medullary lamina, involuted around the dentate fissure ; **, termination of this lamina, 

 the fibres here running longitudinally ; 7, superficial neuroglia of the fascia dentata ; *, stratum 

 granulosum. 



in its outer part, a striated aspect ; hence the name of stratum radiatum sometimes 

 used to distinguish this part of the layer (4), By their bases the cells rest upon the 

 white layer or alveus, into which their axis-cylinder processes pass, but there is in 

 some parts a layer of grey matter intervening (fig. 122, 6). 



Superficial to the stratum radiatum, the processes of the pyramidal cells form an 

 arborisation, the branches of which are closely interwoven (stratum laciniosum, 5). 

 Superficial to this are a large number of small cells which give a granular appear- 



