CONTENTS 



PAGE 



Introduction I 



Literature i 



Summary 12 



Whites (table) 13 



Indians (table) 14 



Other races (table) 15 



Clinical material 16 



New observations 19 



New material 20 



Detailed data 23 



Age 23 



Sex 27 



Frequency of exostoses in the two ears 28 



Side 29 



Number 31 



Location 33 



Size 37 



Shapes 39 



Symmetry 40 



Rate of growth 41 



Subdivision 42 



Structure 46 



Nature 47 



Etiology V 49 



True causes " unknown " 49 



" Spontaneous ", nutritive 50 



Congenital 50 



Developmental 51 



Inborn tendency S3 



Heredity 54 



Social status : Occupation 57 



Climate 58 



Food, drink, habits 58 



Constitutional derangements 59 



Gout, arthritic diathesis 59 



Syphilis 61 



Local irritations and inflammation 62 



Salt water 65 



Abscesses, furuncles 66 



Polyps 66 



Mechanical causes and traumatism 66 



Head deformation 68 



Hi 



