38 CONTEMPORARY EVOLUTION OF MAN. 



to hinder faces of lumbar vertebra : negroes, 106 : 100 ; 

 whites, 100 :96. (b) Shortening and widening of cen- 

 tra of lumbar vertebrae, (c) Correlated changes in 

 lower ribs, lumbar vertebrae, and pelvis. Decrease in 

 the number of ribs. Decrease in the number of lum- 

 bar vertebrae. Shifting of pelvis, (d) Variation in 

 coccyx. 



2. The skull, (a) Closure of cranial and facial 

 sutures in higher and lower races. Open cranial and 

 closed facial sutures associated with increased brain 

 action, (b) Teeth. Dental formula of man : I., 2-2 ; 

 C., 1-1 ; P. M.,2-2 ; M., 3-3. Macrodont : Andamanese, 

 Melanasians, Australians, Tasmanians. Microdont : 

 Europeans, Egyptians. Mesodont : Chinese, Indians, 

 Malayans, Negroes. Decrease in number and size of 

 teeth. The third molars degenerating. 



3. Appendicular skeleton. () Shoulder girdle and 

 upper arm. (b) Variation of scapular index, (c) 

 Torsion of humerus. (d) Obliquity of elbow articula- 

 tion. In the evolution of man the lower end of the 

 humerus has gradually twisted outward, turning the 

 hand to the front, extending its range and adapting 

 it to a wider usefulness, (e) Intercondylar foramen. 

 Thirty per cent, skeleton of reindeer period ; twenty- 

 four per cent, skeleton of Dolmen period ; five and 

 one-half per cent, skeleton of Parisian cemeteries, 

 fourth to tenth centuries ; three and one-half per cent, 

 skeleton of present time. (/) Supracondylar foramen. 

 (g) The os centrale of the wrist, (h) Variation in 

 pelvis, (i) Third trochanter of femur. One per cent, 

 in European ; fifty per cent, in Sioux ; sixty-four per 

 cent, in Laplanders ; thirty-seven per cent, in Swedes. 

 (j) Degeneration of foot. 



