NO. 6 EAR EXOSTOSES HRDLICKA 79 



Noniial. that is. primarily devolutionary and not pathological, or- 

 ganic degeneration follows, as a rule, the reduced use of an organ. 

 Examples of it may be observed in human teeth, appendix, the fifth 

 toe, and other parts that in the course of time have become less active 

 and important than formerly. The changes comprise diminution in 

 size, loss of regularity of shape, diminished vital resistance, and a 

 tendency toward elimination of the part. Has the human ear, or at 

 least the external auditory canal, become less useful and necessary 

 to man than it has been in the lower primates and other animals? 

 The changes here, too, aside from the outgrowths, include diminutions 

 in size (lumen), distortions in shape, and occasionally a more or less 

 complete elimination.'' 



Is the underlying process of ear exostoses, then, a degeneration, or 

 merely a disturbed accommodation— a slowly regressive, or but a 

 somewhat inadequate central control of the neuro-vascular system 

 of the parts involved, with the bony abnormalities as secondary mani- 

 festations ? It may be best not to attempt any answer to this question 

 before the rest of the available facts on the subject can be considered. 



ANTIQUITY 



It is not known, and will probably never be determined, when in 

 the existence of man the abnormality of ear exostoses made its first 

 appearance. No case of the growths has as yet been reported in 

 early (geologically ancient) man, and none even from the Neolithic 

 period, though that does not necessarily mean that they were absent. 



The oldest skulls in which ear exostoses have been encountered so 

 far are the seven skulls with such outgrowths found by me in the 

 Egyptians of the beginnings of the XII Dynasty, or close to 4,000 

 years ago. These specimens came from the deep rock-tombs at Lisht 

 and belonged to the higher classes of the people. 



The four next oldest specimens with ear exostoses are the skull of 

 an Egyptian (date?) reported by Ostmann (1894), that of an early 

 Christian Nubian Egyptian mentioned by Wood Jones (1910), and 

 the two Egyptian crania found by me in the collection from the Kharga 

 Oasis. Possibly quite as old. or nearly so, are some of the pre- 

 historic American Indian skulls with the growths. Most of the Ameri- 

 can specimens of such a nature are pre-Columbian ; others are post- 

 Columbian but of a period before there was any appreciable influence 

 bv the white man. The Hawaiian and New Zealand crania of our 



" See the writer's " Seven prehistoric American skulls with complete absence 

 of the external auditory meatus." Amer. Journ. Phys. Anthrop., vol. 17, no. 3, 

 193.3- 



