FOREWORD 



THE literature concerning the embryology, later develop- 

 ment, and adult anatomy of the nasal accessory sinuses 

 is rather abundant, yet the differences in the views expressed 

 especially concerning the extent of development during 

 the years of childhood seemed sufficiently great to warrant 

 further study. 



The author therefore has collected and carefully studied 

 this series of preparations of the accessory sinus areas 

 which series covers the various stages of development from 

 the sixtieth day of intrauterine life to advanced maturity 

 hoping to supply information regarding some few points 

 with which we. have been imperfectly acquainted, on ac- 

 count of the scarcity of specimens showing the conditions 

 present during the years of childhood. 



Deductions drawn from a few observations are open to 

 fallacy, owing to variations in the extent and type of de- 

 velopment as found in different specimens of approximately 

 the same age. In this series an endeavor has been made to 

 obtain a sufficient number of cases showing the various 

 stages of development to make the general averages of prac- 

 tical value. 



The bodies of children between the ages of two and six- 

 teen years being seldom obtainable in the dissecting rooms 

 of European institutions as well as in America, it was neces- 

 sary, in order to complete such a series, to develop a technic 

 by which the accessory sinus areas could be removed en 



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