CH. LY.] 



THE OLFACTOKY APPARATUS 



785 



" The olfactory bulb has a more complicated structure ; above there 

 is first a continuation of the olfactory tract (white fibres enclosing 



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FIG. 484. Nerves of the septum nasi, seen from the right side. . I, the olfactory bulb; ], the 

 olfactory nerves passing through the foramina of the cribriform plate, and descending to be distri- 

 buted on the septum ; 2, the internal or septal twig of the nasal branch of the ophthalmic nerve ; 3, 

 naso-palatine nerves. (Prom Sappey, after Hirschfeld and Leveille.) 



neuroglia); below this four layers are distinguishable; they are 

 shown in the accompanying diagram from Eamon y Cajal's work, 

 the histological method used being Golgi's. 



FIG. 485. Nervous mechanism of the olfactory apparatus. A, bipolar cells of the olfactory apparatus 

 (Max Schultze's olfactorial cells) ; B, olfactory glomeruli ; C, mitral cells ; D, granule of white 

 layer; E, external root of the olfactory tract; F, grey matter of the sphenoidal region of the 

 cortex ; a, small cell of the mitral layer ; 5, basket of a glomerulus ; c, spiny basket of a granule ; 

 e, collateral of the axis-cylinder process of a mitral cell ; /, collaterals terminating in the molecular 

 layer of the frontal and sphenoidal convolutions; g, superficial triangular cells of the cortex; 

 h, supporting epithelium cells of the olfactory mucous membrane. (Ramon y Cajal.) 



(1) A layer of white fibres containing numerous small cells, or 

 "granules" (D). 



