PLATE 1 



EXPLANATION OF FIGURES 



1 Dog. 18. Ablation of the posterior two-thirds of the left cerebral hemi- 

 sphere, including the basal portion of the temporal lobe and motor cortex. This 

 dog showed typical increase in nystagmus when slow component was directed 

 opposite to the side of the lesion. Quick component was present when rotated in 

 either direction. 



2 Dog 31. Complete left hemi-decerebration, including destruction of the 

 left half of the thalamus. See table 3. Seen from injured side. 



3 Dog 31. Ventral view. Both third nerves and midbrain are intact. This 

 dog showed nystagmus when rotated in either direction with an increase as shown 

 in table 3. a, Third nerves. 



4 Dog 32. Complete left hemi-decerebration, including destruction of left 

 lateral and middle portions of the thalamus and anterior left half of midbrain. 

 Nystagmus was absent in this dog which lived only three days, a, Right third 

 nerve intact; b, left third nerve absent with injury to midbrain. 



5 Dog x. Hemi-decerebration. a, Thickened dura; b, section made through 

 fibrous tissue for examination of thalamus, which showed areas of degeneration. 



6 Dog 5. Complete left hemi-decerebration with injury to lateral portion of 

 thalamus done in two operations. Posterior two-thirds of right cerebral hemi- 

 sphere removed at a third operation. There was an increase in nystagmus when 

 the slow component was opposite to the side of the fresh lesion. The quick com- 

 ponent was present when rotated either direction. Dog was killed three days 

 after the third operation by another dog. See table 3. a, Temporal muscle drawn 

 inwards through defect in the skull; b, thickened dura; c, hemorrhagic remaining 

 portion of cerebrum (the only cortex present); d, fornix. 



7 Rabbit III. Left hemi-decerebration with injury to lateral portion of 

 t lie thalamus. See table 3. a, anterior quadrigemina. 



8 Rabbit VII. Complete decerebration and destruction of the thalamus. 

 ". Anterior quadrigemina; b, optic nerves and chiasma. 



!) Rabbit VI. Complete decerebration and destruction of the lateral portions 

 of the thalamus, a, anterior quadrigemina; b, optic nerves and chiasma. 



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