NO. 6 EAR EXOSTOSES — HRDLICKA 23 



can groups in the frequency of these growths, is seen to be barely in 

 the middle of the American range of their frequencies. 



Additional details of importance regarding the development and 

 prevalence of the abnormalities under consideration on the American 

 continent, and of their significance, will be dealt with in succeeding 

 sections. 



DETAILED DATA 



AGE 



Older observations. — The youngest subject in whom an exostosis in 

 the external auditory canal has so far been observed, recorded by 

 F'ield (1878a), was a girl of 3 years, in whom the bony growth fol- 

 lowed the removal of a polyp. This being by far the earliest age at 

 which the abnormality has been found, the case deserves to be quoted 

 in full : the report reads : 



M. W., a little girl aged 3, was brought to the hospital on July 25th. Her 

 mother states that she had suffered from a severe attack of measles 12 months 

 previously, and that she had since had an offensive discharge from the left ear. 

 I had a few months since removed a polypus. About a fortnight ago, she noticed 

 •i hard substance in the ear, causing the child much uneasiness. When she came 

 to the hospital, a small pedunculated osseous tumour about the shape of a pear 

 was discovered, almost filling up the meatus. 



The individually recorded cases in the young and up to about the 

 age of puberty, that I was able to find in the literature, are as follows : 



Field (1878a), in a girl of 3 Brindel (in Sabroux, 1901), in a boy 

 Alexander (1930), in a boy of 9 of 13 



Tod (1909), in a boy of 10 Alexander (1930), in a girl of 13 



Krakauer (1891), in a girl of 12 Kessel (1889), in a girl of 14 

 Garrigou-Desarenes (1888), in a boy Ferreri (1904), in a girl of 14 



of 12 Bezold (1895), in a boy of 14 



Karewski (1892), in a girl of 13 Green (1879), in a boy of 14 



It may be worthy of note that of the 12 subjects for whom both the 

 individual ages and sex are given, 6 were males and 6 females, a rela- 

 tion which, as will be seen in the next section, does not hold later in 

 life, when the exostoses are much more numerous in the males. 



Bezold (1895, P- 48) mentions an isolated case in a boy of 14; and 

 in addition West (1909) reports a case " in a child of 12 ", who was 

 probably a girl, for the term " child " would scarcely be applied to a 

 boy of that age. 



The great rarity of ear exostoses in children appears most strik- 

 ingly from the data published by Bezold (1885). Examinations by 



