CEREBRAL CORTEX AND VESTIBULAR NYSTAGMUS 



9 



to seven months following the complete hemi-decerebration. One 

 of the animals was kept alive four weeks, the other was killed 

 by a whelping hitch five days after the operation. 



Failure has attended all attempts to produce a complete de- 

 cerebrate dog. All these animals were markedly depressed and 

 comatose and did not live longer than four days. None of these 

 animals manifested the quick component of nystagmus. The 

 slow component, or rotatory deviation, was present in all but 



TABLE 3 



Effect of complete left hemi-decerehration and extensive lesion to the thalamus on the 

 quick component of nystagmus in the dog 



1 Observations are taken from records two days after the operation. For 

 interpretal ion of numbers see fool note to I n hie 2. 



- One to four postrot.alory movements occurred. See table 2. 



3 Eight months after the first operation and five months after the second, the 

 after-nystagmus was six when rotated to the Left, and sixteen when rotated to the 

 right. 



4 Protocol only states that quick component was present when rotated in both 

 di reel ions with a marked increase in the postrotatory nystagmus when rotated 

 opposite t he side of the lesion. 



three. In most instances the slow component disappeared from 

 three to twelve hours before respiration ceased. 



The nearest approach to complete decerebration and destruc- 

 tion of the thalamus in the dog was made in dog 27 (table 3), 

 which was a complete left hemi-decerebrate with destruction of 

 the left lateral portion of the thalamus. This animal lived three 

 weeks. There days before it died its temperature became sub- 



