36 THE NASAL ACCESSORY SINUSES IN MAN 



muschel," and believes that such a condition represents 

 the typical number of conchse originally possessed by all 

 ethmoidal areas at some time in early fetal life. He con- 

 cludes, therefore, that specimens showing fewer conchse 

 do so because of the fusing of two or more of the 

 primitive ethmoidal folds. However, since his own large 

 series of fetuses showed only two specimens in which so 

 many conchas were distinctly differentiated, and since such 

 specimens are so seldom found by other observers of embryo- 

 logic and fetal conditions, it seems more probable that the 

 number found in any given case depends more upon the 

 extent to which differentiation was carried than it does upon 

 the fusing of conchae already formed. Zuckerkandl gives 

 three ethmoidal conchae as the typical number, but found 

 four present in 6.7 per cent, of cases. Seydel found no speci- 

 mens showing more than three, while Schaeffer found four 

 to be rather common. E. Kellius believed the development 

 of five to be very seldom. The nomenclature for the conchae 

 nasales should be applicable to adult conditions and also 

 cover the highest number found in fetal life (Fig. 16). This 

 is satisfactorily done by the terms used by Schaeffer, which 

 are as follows: 



Concha nasalis inferior 

 " media 

 " superior 

 " suprema I 

 " suprema II 

 " suprema III 



The meatus beneath each concha is similarly designated. 

 In my own series of 202 postnatal lateral nasal walls having 



