DEVELOPMENT OF EXTERNAL NOSE IN WHITES AND NEGROES. 



183 



nasal index of negroes is due to the smaller number of individuals in their age 

 groups, in which occasional extreme variants would change the average to a con- 

 siderable degree. The racial difference exists even in the youngest stages studied 

 and is almost exclusively the result of the difference in the nasal breadth of the two 

 races. The averages of the nasal index of negroes are always above 100; only in a 

 few individuals was the index lower. In whites, on the other hand, F' V age groups 

 have an average nasal index below 100. With but few exceptions negro fetuses are 

 hyperchamserrhine; white fetuses are frequently chama?rrhine and even in some 

 cases only mesorrhine. In both races the index drops during the first five months 

 and increases again during the latter part of fetal development, and to a greater 

 extent in negroes than in whites. 



The changes in the nasal index are dependent upon the relation of the relative 

 increases in size of nasal height and nasal breadth. If the relative increase of the 

 former exceeds that of the latter the index will drop; e. g., in the series of whites of 

 the eighteenth week the relative increase of the nasal height was 21 and that of the 

 nasal breadth 10; the index drops, therefore, from 104.6 to 94.7. After birth the 

 nasal index steadily decreases but always shows the racial difference. Only a few 

 races in the adult stage have a nasal index indicating a nasal breadth that is at 

 least equal to the nasal height a very frequent finding in fetuses; among them may 

 be mentioned Australians, Tasmanians, Bushmen, and certain negro tribes. Accord- 

 ing to Broca, the nasal index of the bony nose also decreases during intrauterine 

 development, but here the values are much below the corresponding ones of the 

 external nose as a consequence of the great differ- TABLE lo ._ Nasal indices offelal sA , / ,,., 

 ence between nasal breadth and breadth of the 

 apertura piriformis, the latter being much smaller. 1 

 Table 10 shows Broca's figures for the nasal index 

 in skulls of white fetuses. 



The nasal index stands in correlation with the 

 body-height, the increase of the latter being fol- 

 lowed by a decrease of the former during the en- 

 tire development, Collignon (1887), Houze (1889), 



and Pittard (1911) have shown that this correlation exists also in adults, inasmuch 

 as groups of individuals with greater body-height have a smaller average nasal 

 index than those with smaller body-height. 



That the form of the nose is not correlated to the form of the face can be 

 seen from a comparison of the nasal index and upper facial index in table 8; the 

 latter changes during fetal growth only to a small degree and its averages in negroes 

 are always greater than those in whites ; that is to say, a negro fetus will have a 

 relatively higher face combined with a relatively broader nose than a white fetus. 



The Japanese fetus of the eleventh week had a nasal index of 122.6, the four 

 Filipinos 121.2 in the eleventh week, 137.9 in the fourteenth week, 117.4 in the 

 nineteenth week, and 108.3 in the twenty-first week; the three Indians 123.1 in 



'In fetuses up to the sixth month the width of the apertura is only little more than half the breadth of the external nose. 



