400 



THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



(ganglion cells of retina) as a centre. These olfactory nerves 

 (fig. 239, ri) extend to a stratum glomerulosum consisting of 

 nodulated masses (gl), through the glomeruli of which some 

 small nuclear-like cells are distributed, whilst others are scat- 

 tered around them ; they also contain vessels, but essentially 

 consist of a finely granular mass resembling the matrix of the 



Fig. 239. 



Fig 239, Transparent section of the olfactory lobes of a Monkey. 

 Magnified 100 diameters. n, The olfactory nerve layer; gl, the 

 glomeruli olfactorii ; r, the cortical substance, the ganglion cells of 

 which are most closely aggregated internally (stratum gelatinosum ; 

 gr, granule layers ; m, medullary layers. 



cortex of the cerebrum. The real signification of these clumps 

 of origin for the olfactory nerves, first observed by Ley dig in the 

 Fish, can only be estimated at their true value in Man (fig. 240), 

 in whom the connective tissue, that in animals distends the 

 glomerulus olfactorius to its ordinary size, is defective. Here 



