MOTOR PALLIUM TX REPTILES 477 



With the induced current minimal stimuli were applied at 

 first and increased later in the experiment when it became 

 necessary in order to obtain responses. In many cases the 

 brain fatigued quickly and in some it recovered with equal 

 promptness. Individuals differed greatly as to the recovery. 

 Often when the strength of stimulus was increased struggling 

 movements resulted and the experiment had to be discontinued. 

 In some cases also, the animals gave definitely localized responses 

 to the first stimulation and later, probably because of recovery 

 from the anaesthesia, gave irregular and prolonged reactions. 



COIMICAL REACTIONS IN TIHTLKS 



If we take into account only the short contraction of restricted 

 groujis of muscles, the following jiarts of the hemisi)here have 

 been found to give nmscular responses: dorsal surface of the 

 olfactory bulb, retraction of the neck, extension of the legs, 

 movements of eyeball and eyelid: dorsal surface of jiallium near 

 olfactory ])eduncle and lateral liorder of pallium in the anterior 

 one-half or two-thirds of hemisphere, movements of eyes, jaw, 

 neck, legs and tail; striatal area, movements of all parts. Xo 

 responses were ol^tained from any other part of the dorsal sur- 

 face or llic medial w;ill or from the tuberculum olfactorium, the 

 amygdaloid eminence or elsewhere, except that contractions 

 typical of thalamic stimulation were sometimes obtained when 

 the caudal pole or amygdaloid eminence was being ex]>lored. 

 These were probably due to spread of current to the thalanuis. 



The responses from the striatal area were presumably due to 

 the direct stimulation of descending fibers in the crus. The 

 responses from the olfactory bulb may be due to the close proxim- 

 ity of the 'motor area' which is indeed overlapped by the caudal 

 border of the olfactory formation. Thus it appears that a 

 somewhat comma-shaped area involving the rostral and lateral 

 boi'ders of the general pallium (fig. 1) may be regarded as a 

 motor area in the turtle's pallium. This area corresponds roughly 

 to the 'pallial thickening' described in a previous paper ('15 b). 



Not enough experiments have been conducted under uniform 

 conditions to furnish a basis for the discussion of localization 



