ON THE MAMMALIAN NERVOUS SYSTEM. 275 



excitation of reflex centres (ScniFF, CHAUVEAU). Consequently, it must be under 

 stood that the following enumeration of facts is written and arranged in the light of 

 our experimental results, set forth in the present paper. 



A. Corona Radiata. 



(1.) Latent Period. The loss of time intervening between the moment of appli 

 cation of the stimulus to the corona radiata and the commencement of the resulting 

 muscular contraction is usually 04 sec. (FRANCK and others.) 



(2.) Excitability. The excitability of the fibres rapidly fails upon their exposure. 

 VULPIAN showed that relatively the excitability of the corona radiata was higher 

 than that of the cortex. In this he was confirmed by the observations of BOCHE- 

 FONTAINE, GOUTY, ASCH and NEISSER, and others. 



(3.) Mode of Discharge. The muscular contraction may be (a) a single twitch, or 

 (b) a tonus. The combination we have termed the complete cortical discharge, and 

 consisting of tonus and clonus, is never seen where the cortex is absolutely removed. 

 (FEANCK, BUBNOFF and HEIDENHAIN in part, HORSLEY, SCHAFER and HORSLEY.) 



(4.) Nature of the Discharge. (a.) The tonus observed is regarded as a fusion 

 of muscular responses which commence and end sharply with the beginning and end 

 of the excitation. 



(b.) The rate of recurrence of the individual responses is unknown. 



(5.) Relation of the Discharge to the Parts of the Body. Localisation of gross 

 divisions of the body to certain fields of fibres issuing from cortical centres (all authors 

 named above). 



B. Internal Capsule. 



(1.) Excitability. The excitability of the fibres forming the internal capsule is 

 very high. (FRANCK, GLIKY, BEEVOR and HORSLEY.) 



(2.) Mode of Discharge. Indistinguishable from that of the corona radiata, quod 

 vide. 



(3.) Nature of Discharge. Ditto. 



(4.) Relation of the Discharge to the Parts of the Body. (a.) Localisation of the 

 representation of the gross divisions of the body to limited fields of fibres. (FRANCK 

 and PITRES, GLIKY, BEEVOR and HORSLEY.) 



(b.) Localisation of the representation of segments of the gross divisions of the 

 body to definite fields of fibres. (BEEVOR and HORSLEY.) 



(c.) Localisation of the representation of the character of various movements of 

 segments to definite fields or bundles of fibres. (BEKVOR and HORSLEY.) 



C. Crus Cerebri. 



(1.) Excitability. The excitability of the fibres has been determined by many 

 observers. (BUDGE and others.) 



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