398 



THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



In regard to the statement made by some authors, that they 

 have found pavement epithelium in the ventricles, it may be 

 observed (1) that no satisfactory conclusion can be drawn from 



Fig. 238. 



Fig. 238. T ransparent sagittal section of the brain of a Dog. FO, 

 The lobes of the cerebrum ; 8, the transverse limb of the sulcus cru- 

 ciatus of Leuret ; F, the frontal portion of the cerebrum, formed from 

 the gyrus fornicatus ; jK, the olfactory lobes ; R' ', the olfactory bulb ; 

 V V, the cavity of the olfactory lobe in communication with the lateral 

 ventricle ; C C, the medullary portion of the olfactory lobe that is 

 continuous with the anterior commissure and the transverse section of 

 the anterior commissure which meets this medulla ; the whole tract de- 

 scribes an arch, which for a short distance is truncated, and is directed 

 outwards ; m, the medulla of the bulbus olfactorius ; m', m 1 , medulla 

 of the olfactory lobe which enters the nucleus caudatus ; L, basal por- 

 tion of the nucleus caudatus (region of the anterior perforated plate) ; 

 N (7, head of the nucleus caudatus, continued in the form of an arch 

 into the basal portion ; P, pes or crusta of the cms cerebri, communi- 

 cating with the caudate nucleus ; Th, the optic thalamus, connected 

 with fasciculi that arise from the cortex of the frontal portion of the 

 cerebrum; II, optic nerve; 6r, fornix ; T, corpus callosum ; A, cornu 

 Ammonis ; m/, medulla of the olfactory lobe, running backwards into 

 the gyrus fornicatus. 



a bird's-eye view, and (2) that, in fine profile sections, the 

 attenuated extremity of the cells, with the fibres proceeding 

 from them, are as readily cut off as are the processes of the 



