88 Dr Stone on the Frontal Sinus. 



specimen B, the septum inclines to the left. In specimen D (same 

 case) it inclines to the right. 



In the collection of crania labelled by Dr Spurzheim, now in the 

 Edinburgh College Museum, and which Professor Jameson permitted 

 Sir William Hamilton to open, the septum appears in a great many to 

 have been incomplete ; that is, not extending from the posterior to the 

 anterior wall of the sinus. As Bertin and other anatomists have ob- 

 served, in such crania, the sinus of the right communicates with the 

 sinus of the left side. 



3. Palfin, Sabatier, Monro secundus, and other anatomists, have stated 



that the frontal sinus is often divided by many complete septa ; but in 

 upwards of one hundred crania, not one appeared corresponding to 

 this description. 



4. The frontal sinuses are on each side generally unequal in size ; but the 



remark of Vieussens is not correct, that the right cavity is always 

 larger than the left, (quorum dexler sinistro semper amplior est •). 

 In the collection preserved in the Natural History Museum, speci- 

 mens 42 and 47 will be found to have the left larger than the right 

 sinus ; but in the specimens 9, 5, 4, 26, the right sinus is larger than 

 the left. Many anatomists have remarked, that the sinuses are on 

 each side generally equal ; but this is evidently incorrect. It may, 

 however, be stated, that the right sinus is more frequently larger than 

 the left, than the left is larger than the right sinus. 



In some instances the sinus is found of its usual size on the right 

 side, and only a mere vestige of its existence on the lefiy as may be 

 seen in specimens 17, 36, 45, of the same collection ; and, in some in- 

 stances, the sinus appears of its ordinary dimensions on the left side, 

 with only its rudimentary cell discernible on the right ; which may 

 be observed in specimens 28, 33, 60, of the same collection. 



5. The non-exisience of the frontal sinus is very rare ; and many anato- 



mists, who have affirmed the contrary, have misguided themselves, by 

 not looking for it in the proper place, — a fact which did not escape 

 the observation of Sabatier, who, contradicting the authority of Fal- 

 lopius on this point, remarks, " C'est sans doute une inadvertence de 

 fia part, car on les rencontrent aisement quand on a la precaution de 

 scier la crane pltis bas qu'a V ordinaire -j-.'* 



It is worthy of observation, that Winslow remarks, " the frontal 

 sinuses are sometimes completely wanting, and in such subjects the 

 internal cavity of the nose is larger than ordinary $•" — I may add, 

 that, in the collection of crania in the Edinburgh University, there 

 are only three specimens in which the frontal sinuses appear to be 

 wanting; but in each of these, its elementary cell is visible under 

 each OS unguis; — so that not one specimen in this collection com- 

 pletely wants the frontal sinus. 



• Vieussens Neurograph. Univers. lib. i. c. cxvi, p. 103. 



-f- Sabatier, Traitd d'Anat. torn, i, p. 32. 



X Winslow, Anatomy of the Hiunan Body, p. 23. 



