184 'Journal of Cojuparative Neurology and Psychology. 



note deals with the type of plexus according to the origin and combination of 

 branches. Seven types are recognized: A. With outer cord formed from the 

 4th to the 7th nerves inclusive, the inner from the 7th to the 9th, the posterior 

 from the 4th to the 8th, occurred in .57 per cent of cases; B, like A except posterior 

 cord which was formed from the 4th to the 9th in 1. 71 per cent of cases; C, with 

 outer cord from 4th to the 7th, inner from 8th to the 9th and posterior from 4th 

 to 9th, in 58.28 per cent of cases; D, like C except outer cord from 4th to 8th in 

 2.28 per cent of cases; F, with outer from 5th to 7th, inner from 8th to 9th, posterior 

 from 5th to 9th, in 29.77 P^"^ ^^"t of cases; G, like F, except the 5th sends a branch 

 to the 4th, in 6.85 per cent of cases; H, like G, except the outer cord from the 5th 

 to the 9th, in .57 per cent of cases. No record was made of the relation of the loth 

 spinal nerve to the plexus. Attention was also called to the outer head of the ulnar 

 nerve which when searched for will be found in over 50 per cent of the cases. 



A Racial Peculiarity in the Temporal Lobe of the Negro Brain. By Robert 

 Bennett Bean, University of Michigan. 



Measurements were made of 236 temporal lobes, 54 from white brains and 182 

 from negro brains. Six measurements were made from fixed points on each tem- 

 poral lobe, at three levels, two at the base (antero-posterior and transverse), 2 

 at I cm. toward the pole, and 2 at 5 mm. from the tip of the temporal lobe. At 

 each level, the lobe is smaller in the negro, more nearly approaching the white in 

 size at the base, and diverging from the white in size as the pole is approached. 

 The widest divergence is found in the transverse measurement about the middle 

 of the temporal lobe. There is a variable difference with a mean of about 5 mm. 

 in each measurement. The temporal lobe of the negro is more slender than that 

 of the white, narrower transversely, and more pointed at the extremity, the length 

 being about the same in each race. The differences in general conform to the 

 other characteristics previously described in the negro brain. 



Supplementary Report regarding the Innervation of the Leg of Rana virescens. 



By Elizabeth H. Dunn, Department of Anatomy, University of Chicago. 



A partial report upon this material was made at the 1905 meeting of the Associa- 

 tion. The histological examination of the muscle on the operated side in which 

 all the efferent neurones were degenerated, shows but a slight change from the 

 normal. The cross striations were not obliterated and the nuclear staining was 

 unaltered. The staining with acid dyes was slightly less deep in the muscles of the 

 operated side. The bulk of muscle seemed unchanged. 



As the counting was done upon osmic acid material, only medullated nerve 

 fibers entered into the enumerations. On the intact side, both afferent and efferent 

 fibers were present. On the operated side, the efferent fibers had been eliminated, 

 and the count was of afferent fibers destined for the skin and for the muscles. 

 Among both the afferent and the efferent fibers, splitting occurred. This splitting 

 was in the main trunks of the various segments of the leg. In both classes, the 

 proportion of splitting fibers increases progressively from the thigh to the foot. 



A greater amount of splitting occurred among the purely afferent fibers of the 

 operated side than among the mixed nerves of the intact side. Hence the propor- 

 tion of splitting afferent fibers is greater than that of splitting efferent fibers. This 

 splitting seems to occur in both the cutaneous and muscular afferent fibers. This 

 result carries with it some important physiological corollaries, as for instance that 



