484 HANDBOOK OF PHYSIOLOGY. 



corresponds with an apparatus of ganglion cells in the anterior cornu 

 either on the same level, or even above or below, that when this fibre, or 

 set of fibres, is stimulated, very complex co-ordinated movements occur 

 such co-ordinated movements having been set up by impressions from 

 a connected system of ganglion cells, sent out into the motor nerve fibres 

 which arise from them. In other words, it appears to be probable that 

 in the gray matter of the anterior cornua of various sections of the cord 

 are contained the apparatus for various complicated co-ordinated move- 

 ments. The apparatus of each co-ordinated movement may be set in 

 motion either by sensory impressions passing to the cord, when the re- 

 sult of movement would be a reflex action, or by an impression travelling 

 downwards from the brain, and conveyed by one or more pyramidal 

 fibres. 



Division of the anterior pyramids of the medulla at the point of de- 

 cussation (2, Fig. 334), is followed by paralysis of motion, never quite 

 absolute, in all parts below. Disease or division of any part of the cere- 

 bro- spinal axis above the seat of decussation (1, Fig. 334) is followed by 

 impaired or lost power of motion on the opposite side of the body; while 

 a like injury inflicted below this part (3, Fig. 334) induces similar, never 

 quite absolute no doubt, on the corresponding side. 



When one half of the spinal cord is cut through, complete anaesthesia 

 of the other side of the body below the point of section results, but there 

 is often greatly increased sensibility (hyperaesthesia) on the same side- 

 so much so that the least touch appears to be agonizing. This condition 

 may persist for several days. Similar effects may, in man, be the result 

 of injury. 



In addition to the transmission of ordinary sensory and motor im- 

 pulses, the spinal cord is the medium of conduction also of impulses to 

 and from the Vaso-motor centre in the medulla oblongata, although it 

 probably contains special vaso-motor centres of its own. 



It will be seen in Chapter XXI. that Gaskell considers that the white 

 visceral branches from the spinal cord to the sympathetic system are con- 

 nected with or arise from the posterior vesicular column of Clarke, and 

 from the anterior lateral cells. Others think that the direct cerebellar 

 tract arises from Clarke's column. 



ransference. Examples of the transference of impressions in the 

 cord have been given (p. 466); and that 'the transference takes place in 

 the cord, and not in the brain, is nearly proved by the frequent cases of 

 pain felt in the knee and not in the hip, in diseases of the hip; of pain 

 felt in the urethra or glans penis, and not in the bladder, in calculus; 

 or, if both the primary and the secondary or transferred impression 

 were in the brain, both should be felt. 



