458 



The Frontal Sinuses of the Bos Biuffalus. 



large and deep anteriorly, the sphenoid considerably depressed, 

 optic foramina small, the structure of the whole dense and 

 heavy, the diploe in some places scarcely distinguishable from, 

 the external tables, which are hard as flint. It will be seen by 

 the cut that the frontal forms a huge protecting shield over the 

 brain-case, and that it projects right and left by horn-like pro- 

 cesses, and is throughout its whole bulk divided into a series 

 of partitions or sinuses, the walls of which are arranged sym- 

 metrically. They are very dense, and the spaces between them 

 vary in form and size, though if a vertical line be drawn through 

 this portion of the skull at the sagittal suture, the sinuses on 

 one side are very exact counterparts of those on the other. 

 From the upper exterior edge of the frontal at the sagittal 

 suture, to the sectional line over the foramen magnum, the mea- 

 surement is 7f- inches. The extreme width of the frontal, mea- 

 sured from the extreme points of the horn-like projections is 

 H5- inches. The two lateral sinuses differ slightly in size ; that 

 on the left hand in the cut, measures 3|- inches in length, and 

 If inches across at its widest part, by a line drawn across it 

 vertically. The other has a length of 3f inches, and If inches 

 respectively. The loss of a portion of the intersecting walls of 

 the sinuses to the right of the sagittal suture, was owing to an 

 accident in making the section, owing to the extreme hard- 

 ness of the bone. The cavity of the cerebrum is, in the 

 opinion of the writer, proportionately large, but this opinion is 

 hazarded in the absence of means of comparison with similar 

 sections. In the section the measurement across at the line of 

 the two wings of the sphenoid is 4| inches, and vertically, from 

 the central dip of the inferior surface of the frontal to the supe- 

 rior ridge of the temporal, over the foramen magnum, is 5 inches. 

 It was not possible to measure the internal capacity of the 

 brain-case in this instance, the portion of the skull figured 

 being the only one which remained for leisurely examination, 

 and that was kept solely on account of the curious conforma- 

 tion of the sinuses. 



No doubt many reasons may be conjectured to account for 

 the peculiar structure of the frontal. It evidently possessed 

 immense strength, both for the support of the horns and for 

 their use as weapons of offence. But it is worthy of remem- 

 brance that this buffalo is semi-aquatic in its habits, and thrives 

 best in regions most infected with malaria. May not the 

 sinuses be in some way connected with the function of respira- 

 tion, to enable the creature to bear submersion for some length 

 of time while fording a stream, or when taking shelter in the 

 swamp from the myriads of insects which annoy it? 



