144 ELEMENTS OF HISTOLOGY. [Chap. xvn. 



of the medulla comprises all parts of the lateral 

 column of the cord including that portion which was 

 mentioned as the anterior root-zone and the direct 

 cerebellar fasciculus, but not that posterior division 

 of it which was mentioned previously as the fasciculus 

 of Turk, or the crossed pyramidal fasciculus. 



(d) The posterior column of the white matter of the 

 cord is continuous with the same column of the medulla. 

 That portion of it which lies next to the posterior 

 median fissure, and which is called in the cord the 

 fasciculus of Goll, is in the medulla called the fasciculus 

 (or funiculus) gracilis. In the upper part of the 

 medulla, as the central canal opens iato the fourth 

 ventricle, the fasciculus gracilis turns obliquely out- 

 wards, and forms the lateral boundary of the ventricle. 



187. (e) The lateral part of the posterior column of the 

 cord, which was mentioned as the fasciculus cuneatus, is 

 prolonged into the medulla under the same name. But 

 between the two i.e., the fasciculus gracilis and fasci- 

 culus cuneatus there exists another tract, which is 

 called by Schwalbe funiculus of fiolando. In the 

 upper part of the medulla the fasciculus cuneatus 

 becomes covered by transverse bundles of medullated 

 nerve-fibres; these pass from the anterior median 

 fissure across the surface of the pyramids and olivary 

 body in a transverse direction towards the posterior 

 fissure, but before reaching this take an upward 

 direction. These bundles are the external arcuate 

 fibres. In the upper part of the medulla the ex- 

 ternal arcuate fibres, part of the funiculus cuneatus 

 and funiculus of Rolando, as well as the direct cere- 

 bellar fasciculus of the lateral column, all join to form 

 a prominent tract of white matter the corpus resti- 

 forme which enters the white matter of the cerebellar 

 hemisphere on the same side ; this is the pedunculus 

 cerebelli ad medullam oblonyatam, or the lower cere- 

 bellar peduncle. 



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