NO. 6 EAR EXOSTOSES — HRDLICKA 5I 



explained as a peculiarity of the race, must be considered as congenital 

 deformities." 



Fiirst (q. by Moller-Holst, 1932, p. 73) regarded the exostoses as 

 possibly congenital, and Green (ibid.) held that some of the growths 

 could be of fetal origin. 



All ideas of congenitality are. on the other hand, opposed strongly 

 by Kessel ( 1889, p. 286) , who states : "In the literature of the subject 

 there are also met with opinions that the exostoses in the auditory 

 canal may occur congenitally. In my estimate this assumption rests 

 on a gross error, for from developmental studies it is known that in 

 the newborn there is as yet no bony meatus and that the same comes 



into existence only during the first years of life The exostoses 



are therefore later manifestations " Le Double and Lebourg 



(1903) express the view that the growths "evidently are not con- 

 genital"; and Korner (1904) states unequivocally that they do not 

 occur congenitally. 



New observations. — An examination of numerous skulls of fetuses, 

 newborn, and infants has shown me not the slightest trace of what 

 could be regarded as a hyperostosis or exostosis of the tympanic ring, 

 or on the roof of what was becoming the external meatus. As Kessel 

 pointed out, there is no bony canal until well after birth, in early 

 childhood. 



Judging from the incomplete developmental stage of the parts up 

 to and for a period after birth, and from the absolutely negative results 

 of our examinations, which included infant skulls of groups that were 

 greatly affected by ear exostoses in later life, it may safely be said, 

 I think, that the growths in question do not occur congenitally. The 

 term " congenital " should henceforth be excluded from the literature 

 of ear exostoses. 



DEVELOPMENTAL 



Aside from causes inherent in the organism and derived either from 

 some constitutional fault or from heredity, a number of students of 

 ear exostoses connect them with " developmental " conditions of the 

 external auditory canal. Just what is meant by this is mostly not clear, 

 and even where an attempt is made at explanation, no proof of the cor- 

 rectness of the view is given in any instance. 



Virchow (q. by Moller-Holst, 1932, p. 73) believed that some of 

 the exostoses originated in the fetal stage from the tympanic ring as 

 a result of a pathological irritation. Much the same view was held 

 by Moos. Green, too, believed that some of the growths could develop 

 in fetal life. For Heiman ( 1890) congenital ear exostoses were " due 



