NORMAL HISTOLOGY. 



The several structures composing the cornu Ammonis, examined 

 from the ventricle towards the outer surface, are 



i. The alveus, an attenuated layer of medullated nerve-fibres, 

 homologous with the medullary substance of the typical convolu- 



m 



C 



Section across cornu Ammonis, fascia dentata, and fimbria : Gh, hippocampal convolution ; 

 Fd, fascia dentata, separated from preceding by hippocampal fissure ; Fi, fimbria, composed 

 of transversely cut longitudinal nerve-fibres; i, 2, medulla of hippocampal convolution con- 

 tinued over cornu Ammonis (C), as alveus, into fimbria ; 3, layer of large pyramidal cells ; 4, 

 stratum radiatum ; 5, stratum lacunosum ; 6, stratum moleculare ; 7, lamina medullaris 

 involuta ; tn, termination of this lamina in longitudinal fibres ; , nucleus fascia; dentatae ; g, 

 stratum granulosum ; r, reticulated neuroglia-layer covered by thin sheet of nerve-fibres. 

 (After Henle.) 



tion. The fibres, while pursuing a course generally parallel to the 

 ventricular surface, run somewhat obliquely ; on approaching the 

 fimbria the layer increases in thickness and the nerve-fibres assume 

 a disposition less oblique, until, within the fimbria, their direction 

 almost coincides with the long axis of the cornu Ammonis. 



