•)]•) ANX \LS .V/v'ir YOh'K AGADEMY OF .sr//;.Vf /;,s' 



jnst wliiit would naturjilly hapiK'ii if tho loss of hair wcro due to tiu; weariufr 

 of clotlu's, — at lirst and for a Ioii.lc time, a slviii tlirowii over tlie sliou'.dor.s and 

 tied around tlic waist. But if the loss of iiair were coiiditionod by dinitite it 

 should, as it invariably docs among animals, disappear first on the under side 

 of the body and the limbs and be retained lon^'est on tlie l)aek and shoulders. 



It will not be questioned tliat the higher races of man are adapted to 

 a cool-temperate climate, and to an cnvirdiiment rather of open grassy 

 plains than of dense moist forests. In such couditinus they roach their 

 highest physical, mental and social attainments. In the tropical and 

 especially in the moist tropical environment, the physique is poor, the 

 death rate is higli, it is dillicult to work vigorously or continuously, and 

 especial and unusual precautions are necessary for protection from dis- 

 eases and enemies against which no natural immunity exists and which 

 are absent from tlie colder and drier ('n\ ironment. 



This lack of adaptation to tropical ch'mate is also ti'ue, aHliougli to a 

 less degree, of the lower races of man. Aithougli tiom prolonged resi- 

 dence in tropical climate they have acquired a partial immunity from the 

 environment so unfavorable to the newcomer, yet it is by no means com- 

 plete. The most thoroughly acclimatized race — tiie negro — reaches his 

 highest physical development not in the great equatorial forests but in the 

 drier and cooler highlands of eastern Africa; and when transported to 

 the temperate United States, tlie West Coast negro yet finds the environ- 

 ment a more favorable one than that to which his ancestors have been 

 endeavoring for thousands of years to accustom themselves. In tropical 

 South America, the Indians, as Bates long ago remarked, seem very im- 

 perfectly acclimatized and suffer severely from the hot moist weather; 

 much more than the negroes, whose adaptation to tropical climate has 

 been a much longer one. 



In view of the data obtainable from historical record, from tradition, 

 from the present geographical distribution of higher and lower races of 

 men, from the physical and physiological adaptation of all and especially 

 of the higher races, it seems fair to conclude that the center of dispersal 

 of mankind in prehistoric times was central Asia north of the great Hima- 

 layan ranges, and that wlu'ii by progressive aridity that region became 

 desert it was transferred to the regions bordering it to the east, soutli and 

 west. We may further assume that the environment in which man ]iri- 

 marily evolved was not a moist or tropical climate, but a temperate and 

 more or less arid one, progressively cold and dry during the course of his 

 evolution. In this region and under these conditions, the race first at- 

 tained a dominance which enabled it to spread out in successive waves of 



