408 CHARLES CLIFFORD MACKLIN 



underlying cartilage by a thin sheet of perichondrium, and be- 

 tween it and the processus maxillaris posterior the anlage of the 

 lacrimal duct may be seen. The lower surface of the prominence 

 is rounded, and thus contrasts sharply with the lower border of 

 the planum antorbitale immediately dorsal to it, which is sharply 

 marked, and projects outward and. downward beyond the prom- 

 inence. 



The cranial area of the ventral surface presents a smaller 

 eminence, the prominentia superior (figs. 1, 3 and 12), to whose 

 dorso-lateral edge the sphenoethmoidal conmiissure is attached 

 and which medially goes over into the septum. It is to be found 

 just ventral to the fenestra cribrosa, and the small foramen 

 epiphaniale (fig. 3) is to be seen piercing its ventro-lateral edge. 

 It represents a small cavity, found in the inner capsular wall. 

 This prominence is separate from a larger one, situated upon 

 the lateral wall, some distance in front and below, which I regard 

 as the structure called by Voit the Sakterwulst in the skull of 

 the rabbit. Between these prominences a shallow furrow may 

 be observed, and this opens below into a prominent pit, delimited 

 by the Sakterwulst, and the superior and posterior prominences. 

 This pit corresponds, I believe, to the sulcus lateralis anterior 

 which Voit describes in the skull of lepus, and it follows that the 

 region dorsal to it must represent the wall of the recessus lateralis. 

 »The latter is, however, very rudimentary in man, and the corre- 

 sponding area of the lateral wall in my model appears to be col- 

 lapsed, when compared with the condition in the rabbit as shown 

 by Voit's illustrations. The anterior prominence of Voit is not 

 to be seen. 



The Sakterwulst (supraconchal prominence) is the most con- 

 spicuous of all the prominences in the human ectethmoid at this 

 stage,' and presents a sharply-marked summit. Behind the lat- 

 ter may be seen an undulating ridge, which passes successively 

 backward, across the sulcus lateralis anterior, over the ridge of 

 the posterior prominence, to reach the lower border of the planum 

 antorbitale (fig. 3). The Sakterwulst corresponds to the ventral 

 extremity of the middle meatus of the nose; below it is a groove 

 leading downward and backward to an incisure in the lower 



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