68 OBSERVATIONS AND MEASUREMENTS ACADEMY MEMBERS 



[Memoirs National 

 [Vol. XXIII, 



The Ear 



The dimensions of the ear vary considerably with race, sex, stature, age, and individuals, 

 fn general the left ear alone is measured, as the more convenient. The usual measurements 

 are the greatest length with the greatest transverse breadth, and the percental relation of the 

 latter to the former gives the ear index. The three determinations may well be dealt with 

 together. 



Table 53. — Ear length 



Members of the Academy 



Old Americans 



Not old Americans 



Old Americans 

 at large (labora- 

 tory series) 



Subjects 



Average 



Minimum 



Maximum 



Range of variation in percentage of the average 



a 



cv 



92 



7. 02 ±0. 031 



6. 1 



8. 4 



82. 76 



0. 447 ±0. 022 



6. 36 ±0. 32 



49 



7. 07 ±0.043 



6. 1 



8.3 



SI. 13 



0. 444 ±0. 030 



6. 29 ±0.43 



250 

 6.70 



5.5 



8. 1 

 38. 81 



DISTRIBUTION 



7.3-7.5 



7.6-7.8 



Old Americans (92) 



Not old Americans (49) _ 



Percent 

 9.8 

 4. 1 



Percent 



9. 8 



12.3 



Percent 

 19. 6 

 26. 5 



Percent 

 31. 5 

 26.5 



Percent 

 20. 7 

 16.3 



Percent 



5. 4 



10. 2 



Percent 

 2.2 

 2.0 



Percent 

 1. 1 

 2.0 



EAR LENGTH AND AGE 



Members of the Academy 



Old Americans 



Not old Americans 



Old Americans 

 at large (labora- 

 tory series) 



Subjects to 60 years of age, inclusive 



Average 



a 



CV 



Over 60 years of age 



Average 



Cf 



CV 



55 



6. 90 ±0.041 

 0. 447 ±0.029 



6. 48 ±0. 42 

 37 



7. 21 ±0.041 

 0. 371 ±0. 029 



5. 14 ±0. 40 



22 



6. 89 ±0. 056 

 0. 386 ±0. 040 



5. 61 ±0. 57 



27 



7. 21 ±0.056 

 0. 433 ±0. 040 



6. 00 ±0. 55 



250 

 6.70 



