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MANUAL OF EQUINE MEDICINE. 



mares, and twenty-one geldings, that the weight of the 

 cerebellum is greatest in the latter. 



Experimental lesions of the cerebellum always induce 

 disorders of equilibrium, but never of impairment of sensa- 

 tion or actual loss of voluntary muscular power, and Flourens 

 inferred, therefore, that it controlled and harmonized the 

 various muscular movements, while Foville attributed the 

 manifestations to loss of muscular sense. 



Sympathetic System. — The chief function of the sympa- 

 thetic system is the control of the involuntary muscle-fibre 

 of the body. 



If the branches of the sympathetic supplying the muscle 

 be stimulated, contraction is caused, while section of the 

 nerve is followed by relaxation of the fibres. 



In this manner the calibre of the bloodvessels and the 

 amount of the blood supplied to various organs and tissues 

 is regulated. 



In addition to this indirect influence of the sympathetic 

 upon the nutrition of the tissues, it is very probable that 

 it also exercises a direct influence on the functional activity 

 of the cells in secreting glands and elsewhere. 



The sympathetic system appears to have its supreme 

 centre in the medulla, or rather in its floor; but it is 

 intimately interwoven with the spinal system, for each 

 spinal nerve receives branches from and transmits branches 

 to the neighbouring sympathetic ganglion. 



