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the cord to those of the brain stem. To that end the gray matter of 

 the cord has been removed from the cross section of the lower end. 



The dorsal columns of the cord are clearly shown in the cross 

 section and then a portion of the fibre bundles have been cut away in 

 order to uncover the corresponding nuclei. The connection between 

 the fibre bundles of the dorsal columns and their nuclei is made by 

 wires which show that the fibres take four paths in entering the 

 medulla. 1) The fibres of the fasciculus gracilis enter the nucleus 

 funiculi gracilis. From here a new set of fibres passes across the 

 median line as the decussatio lemniscorum and enters the lemniscus 

 medialis of the opposite side. 2) One bundle of fibres from the fas- 

 ciculus cuneatus enters the nucleus funiculi cuneati lateralis (Blumenau) 

 while fibres enter the corpus restiforme. The fibres which pass directly 

 from the dorsal funiculi to the corpus restiforme are shown on 

 model II. 3) Another group of fibres from the fasciculus cuneatus 

 enters the nucleus funiculi cuneati from whence a new set of fibres 

 pass as fibrae internae arcuatae across the middle fine and enter the 

 lemniscus mediaHs. 4) A set of fibres from the dorsal funiculi enters 

 the formatio reticularis region of the medulla. 



The fasciculi laterales can be traced in the same way. 1) The 

 fasciculus cerebello- spinalis is clearly shown on the right hand side 

 as it enters the medulla, turns dorsalward and passes into the corpus 

 restiforme. 2) The fasciculus lateralis proprius can be separated at 

 this stage into three parts which are shown by wires on the right hand 

 side. The first bundle turns inward as it enters the medulla and 

 probably joins the medial lemniscus. The second passes from the 

 nucleus n. vestibuli lateralis (Deiters) to the spinal cord. The third 

 runs from the cord as far as the corpus trapezoideum. 3) The crossed 

 pyramidal tract is shown by heavy wires. The wires indicating the 

 position of the pyramidal tract for the entire model show best on the 

 ventral surface. 



The ventral columns of the cord consist first of the direct pyra- 

 midal fibres which show best on the ventral surface of the fourth 

 model. The rest of the ventral column fibres show best on the left 

 side of the model or from its dorsal aspect. For the most part they 

 enter the fasciculus longitudinalis medialis. 



The shape of the lemniscus medialis has been emphasized in my 

 previous paper; the perpendicular sheet in the medulla, the horizontal 

 one in the pons and the lateral oblique sheet in the midbrain. The 

 course of the fibres of the fasciculus longitudinalis medialis has been 

 made plain by lines and wires. The descending fibres start from the 



