SECT. 1 1 6.] NERVOUS SYSTEM. 233 



optic thalamus. That is to say, very numerous white bundles, even 

 visible to the naked eye, pass from the hemisphere into the thala- 

 mus in its whole depth, run towards the upper surface, the superior 

 internal border and toward the pulvinar, and are lost exactly like 

 the fibres which are continued from the cerebral peduncle to the 

 corpus striatum ; i. e., these bundles, which at first contained 

 elements of from 0*0012'" to 00025'" in diameter, split up into 

 extremely dense plexuses of the very finest fibres, of from O'ooo^" 

 to o - ooo8'", the true terminations of which cannot be followed. 



I may still notice the structure of the parts which are connected 

 with the above-described ganglia. The substantia nigra of the ce- 

 rebral peduncles contains beautiful pigmeutated cells. The com- 

 missura mollis has smaller cells with processes, and, for the most 

 part, fine fibres. The glandula pinealis contains pale rounded cells 

 without any processes, and but a few nerve-fibres, o - ooi'" to 0-002'" 

 in diameter; and, for the most part, a large quantity of sandy 

 particles (see § 117). The floor of the third ventricle, the corpus 

 mammillare and tuber cinereum, contain nerve-cells mixed with nu- 

 merous fibres of the finest kind. The hypophysis cerebri contains, 

 in its anterior reddish lobe, no nervous elements, but rather, ac- 

 cording to Ecker, the elements of a vascular gland, i. e., a stroma 

 of connective tissue, with very closely packed, wide blood-vessels, in 

 the meshes of which there lie vesicles [cells?], of 0*030 to 0*090 

 of a millimetre in diameter, which sometimes contain only nuclei 

 and a finely granular substance, sometimes distinct cells; in older 

 subjects, also, a substance resembling colloid. The posterior smaller 

 lobe consists of a finely granular substance, with nuclei and blood- 

 vessels, and possesses, also, fine varicose nerve-tubes, which, like 

 the vessels, descend to it from the infundibulum. 



I regard the demonstration, that the fibres of the cerebral peduncle ter- 

 minate in the ganglia (probably in the cells) of the brain, and that the white 

 substance of the hemispheres consists of peculiar tubes, extending from the 

 convolutions into the ganglia, and perhaps, also, into the medulla oblongata, 

 without becoming connected with those of the cerebral peduncle, as one of 

 the most important results which I have arrived at in my investigations into 

 the central nervous system ; seeing that by this means the long supposed 

 separation of the animal and psychical spheres of the central nervous system 

 is for the first time anatomically demonstrated ; and it is explained why the 

 white substance of the hemispheres, when stimulated, occasions neither pain 

 nor movement. 



§ 116. Hemispheres of the Cerebrum. — The white substance of 

 the hemispheres of the brain consists throughout of nerve-tubes, 



