DEVELOPMENT OF EXTERNAL NOSE IN WHITES AND NEGROES. 185 



negroes. The racial difference in the relative interocular breadth is not con- 

 stant during intrauterine growth. During the early part of the latter negroes 

 show a relatively shorter distance between the eyes, but later it frequently exceeds 

 this measurement in whites, and at birth and in postnatal life is always greater. 

 (See curves in figure 5.) During the entire growth the relative interocular breadth 

 changes to a great extent; the highest index (63.2) was found in a white fetus of 

 11 weeks, while the lowest figure (17.2) was observed in an adult white. 



The Japanese fetus of the eleventh week had a relative interocular breadth of 

 41.7; the Filipinos had 45.5 in the eleventh week, 35.2 in the fourteenth week, 27.9 

 in the nineteenth week, and 26.9 in the twenty-first week; the Indians had 33.3 in 

 the sixteenth week, 30.6 in the eighteenth week and 32.6 in the twentieth week. 



Of the few monkey fetuses available for comparison, the relative interocular 

 breadth in the younger macacus was 37.5 and in the older one 54.5 (unquestionably 

 a very rare exception!); the younger gorilla had for this index 27.3, the older one 

 24.5. The relative interocular breadth in these apes, with the 

 exception of the older macacus, was smaller than in correspond- 



ing human stages, but much greater than in the adult macacus 

 and gorilla. Fischer (1903) showed that very young monkey 

 fetuses have a relative interocular breadth which is even greater 

 than the above-mentioned figures and equal that of young human 

 fetuses. The ontogeny of monkeys shows, therefore, a condition 



similar to the human one i. e., a 

 rapid decrease in the relative dis- 

 tance between the eyes in the begin- 

 , ning, but one of greater degree than 



in man, producing a narrower inter- 

 orbital region in adult apes than in 

 ftionHi' year-^ man. (In only a very few adult 



<<H, .ttttft.i,k,7ttam.7. i , .to. 2. aduit monkeys does this index reach the 



FIGURE 5. Curves of the average relative interocular 



breadths. lowest extreme of its range of varia- 



tion in man.) That in the phylogeny of monkeys there exists a broad interor- 

 bital region is proved by the fossil skull of Mesopithecus pentelici, and Schwalbe 

 (1899) found that the Spy and Neanderthal skulls had a relatively broader inter- 

 ocular breadth than modern man. There can be no doubt, therefore, that in the 

 evolution of primates the eyes have come closer together, narrowing the upper 

 breadth of the nose. This is more marked in apes than in man, and is most 

 pronounced in Cebus among the platyrrhines and in Macacus, Cynocephalus, and 

 Cercopithccus among the catarrhines. 



The percentage relation between the nasal breadth and the interocular breadth, 

 or between the lower and the upper nasal breadth, shows great variability in the 

 different age groups. The extremes of the entire material were 55.0 and 153.8. 

 It can be stated that the two nasal breadths do not stand in close correlation. 

 During growth this index increases irregularly, the averages in whites ascending 

 from 70 to 118, and in negroes from 89 to 122. Hence in both races the nasal 



