278 ENDOCRINE GLANDS 



Sacro coccygeal region (Below the II sacral segment). 



They, therefore, form a column divided into three 

 segments. 



Cervical segment. 



Thoracic-lumbar segment. 



Sacral coccygeal segment. 



Between these three segments are two interrupted zones 

 located between the IV cervical segment, and I dorsal 

 segment and between the III IV lumbar segment, and 

 II sacral segment. 



We notice that these zones of interruption correspond 

 to the root of the limbs, and that the intermediary seg- 

 ments correspond to the intermediary zones, above and 

 below these roots. These facts are extremely important; 

 this distribution of the nerve roots shows that in the roots 

 which correspond to the nerve distribution of the limbs, 

 there is, so to speak, no participation to the enervation of 

 the trunk. There is, therefore, no question that these 

 roots do not participate in the vegetative visceral ener- 

 vation and we understand how these vegetative spinal 

 groups become so small that they nearly disappear in 

 these regions. 



(6) Groups derived from the medial ventral mar- 

 ginal zone. 



They form, as far as our present knowledge goes, a 

 column starting below the IV lumbar segment. 



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SENSORY CENTRES. 



I have shown that certain of the nuclei (dorsal) of 

 Stilling-Clarke play a part in the distribution of sensory 

 tracts arising from organic tissues. It is in the anterior 

 portion of the dorsal or internal part of the posterior horn 

 that we must look for the nuclei of the vegetative system. 

 From the point of view of their disposition in height, we 



