MOT(3R PALLIUM IX REPTILES 479 



MOTOR RESPONSES IN I'HE LIZARD 



Only four animals have been examined, two of which gave 

 much clearer and more definite results than those obtained from 

 most of the turtles. From the area shown in the accompany- 

 ing sketch one animal gave movements of the fore leg, jaw and 

 eye mijscles, neck and throat muscles, and anterior body muscula- 

 ture. Stimulation of the olfactory tubercle also caused contrac- 

 tion of small nmscles in the throat, which was felt as the head 

 was held in the fingers. Stinmlation of the crus in the striatal 

 area produced mo\'ements of legs and body muscles. Move- 

 ments of the fore leg were regularly heterolateral, although 

 homolateral movements occurred occasionally. Just the op- 

 posite was true of the eye and jaw muscles. The other animal 

 responded to stinuilation of the anterior part of this area by 

 strong contraction of ])elvic muscles and movements of the hind 

 legs and by weak movements of the fore legs. Stimulation of 

 the lateral border of the right pallium in this animal produced 

 a definite torsioji of the fore part of the body. 



(lerrhonotus is n rather large lizard and its brain is fairly 

 satisfactory to woik witli. The results in these two cases were 

 so definite that I regard them as strong evidence that a motor 

 area exists in the lizard pallium essentially similar in j^osition 

 and extent to that in the turtle. 



Early in my studies I examincMl \\\c brain of a single specimen 

 of Alligatoi' about a foot and a half in length, and obtained 

 motor res})onses from the anterior \vdvt of the dorsal pallium, 

 but I ha\'e no written record of this experiment. 



Fiom these experiments, together with the study of the struc- 

 ture of the hemis])here already reported, I am strongl}' inclined 

 to belie^•e not only .'hat reptiles possess a general or somatic 

 pallium which has been in dispute until recently, but also that 

 in that pallium are to be distinguished definite sensory and motor 

 areas in the sense in which those terms are commonly used of 

 the mammalian pallium. Localization within these areas and 

 the significance of these areas in the evolution of the mammalian 

 paUium are subjects for further study. 



THE JOUHNAI. OF COMPARATIVE NF.UKOLOGY, VOL. 26, NO. 5 



