NO. 6 EAR EXOSTOSES HRDLICKA IJ 



of the mucous membrane of the ear, as a result of rather free Hving " 

 (and drinking) ; and the second associated with " disease in the cavi- 

 ties containing the expansion of the auditory nerve." 



The first " thesis " devoted entirely to the subject of ear exostoses 

 is by Delstanche (1878) ; and in the course of time this is follov^^ed 

 by other such treatises by Schlomka (1891), Braunberger (1896), 

 Sabroux (1901), and Bachauer (1909) ; to v^hich may be added the 

 comprehensive dissertations on the subject by Alexander (1930) and 

 Moller-Holst (1932). 



It would seem that a relatively limited condition that has received 

 such prolonged and extensive attention should be well understood 

 by this time ; but, as will be shown later, this is still far from being 

 true. 



The records of over 200 cases of ear exostoses reported by aural 

 surgeons are given in the next table. The stated nationality is usually 

 that of the author, but the subjects, especially in such complexes as 

 Austria or the United States of America doubtless included various 

 other racial elements. 



The data as to the sex, side, etc., do not always extend to the whole 

 or an equal number of cases reported, which reduces their value. They 

 need not be considered at this juncture ; as far as they go they will be 

 dealt vnth in subsequent chapters. 



The table on page 18 has no pretense to completeness. There are 

 records of additional cases, but some of these are little more than 

 mere mentions, while with others the original report was unobtainable. 



Biirkner (1884, pp. 92-93) summarized the statistical data on ear 

 diseases published by 16 authors to 1884, but combined, regrettably, 

 stenoses, exostoses, and atresiae into one group, and there is no way 

 of separating the three. The figures had nevertheless some interest. 

 In all there were 94 cases of the three above-named conditions, re- 

 ported by 6 authors ; and their combined frequency was, for Gruber 

 0.2; Lucae 0.2; Hedinger 0.3; Newark 0.3; Burkhardt-Merian 0.5; 

 and Schwartze 0.2 percent of all cases with ear diseases. 



What stands out from all the preceding data is the wide distribution 

 of the incidence of ear exostoses, geographically, racially, and also 

 in time. It is no recent or local affliction, but an old and widely gen- 

 eralized disorder. A few racial groups appear immune, but from none 

 of these is there sufficient material to decide the question. In the 

 remainder the frequency varies greatly, and this variance seems to 

 follow racial or geographical affinities, but there appear no few 

 exceptions to this, especially in the American Indian, where group 

 conditions evidently prevail over the racial. 



