THE SEXSORIAL FUNCTION. 147 



other part of these bones is covered by a thick mass of muscle, the tem- 

 poral muscle, which is principally^ concerned in chewing the food, but 

 which likewise, by its yielding resistance, speedily and effectually breaks 

 the force of the most violent blow. A woolpack laung over the Avail of a 

 fortress, when the enemy is battering to effect a breach, renders the 

 heaviest artillery almost harmless. So the yielding resistance of the tem- 

 imral muscles affords a siu'e defence to the brain, however sudden or violent 

 7nay be the blow which falls on the parietal. These benevolent provisions 

 will not be disregarded by the reflecting mind. 



On the side of the head, and under the parietals {d d, p. 14-5) are the 

 temporal hones, one on each side,//. These again are divided into two 

 parts, or consist of two distinct bones ; the petrous portion, so called from 

 its gi"eat or stony hardness, and containing the wonderful mechanism of 

 the ear, and the squamous portion from the appearance of its union with 

 the parietal, overlapping it like a great scale. 



From the latter there projects a portion of bone, e, which unites with 

 the frontal, and forms a strong arch — the zygomatic — distinctly to be 

 felt at the side of the head immediately above the eye. This arch is 

 designed to protect the upper part of the lower jaw, the motion of which 

 may very plainly be seen beneath it when the horse is feeding. It is very 

 strong, and it ought to be, for if it wei'e depressed or forced inward, the 

 horse would starve. There is one species of violence which causes this 

 arch to require no common strength ; and that is, the brutal manner in 

 which the collar is often forced over the head. 



At the base of the arch is an important ca^-ity not visible in the cut, 

 receiving into it, and forming a joint with, the head of the lower jaw — it 

 will be presently desci'ibed. 



Having reached the base of the temporal bone, it is found united to the 

 parietal, not by a simple sutiire, as the lower part of the fi-ontals, or the 

 bones of the nose (see fig. a and j, p. 145), nor by a dove-tailed suture, as 

 the upper part of the frontals (see the same cut), but it is spread over the 

 parietal in the form of a large scale, and hence, as before observed, called 

 the squamous portion of the temporal bone. In fact, there are two plates 

 of bone instead of one. Was there design in this ? Yes, evidently so. 

 In the first place, to increase the strength of the base of the zygomatic 

 arch. This extensive union between the temporal and parietal bones 

 resembles the buttress or mass of masonry attached to the base of every 

 arch, in order to counteract its lateral pi'essure. The concussion, likewise, 

 which might be communicated by a blow on the top of the arch, is thus 

 spread over a large surface, and consequently weakened and rendered 

 compai-atively harmless ; and that surfixce is composed of the union of two 

 bones of dissimilar construction. The hard stony structure of the parietal 

 is very different from the tougher material of the temporal ; and thus as 

 a finger acts on a sounding glass, the vibration communicated to the tem- 

 poral is at once stopped, and the brain receives no injury. 



There is another proof of admirable design. Wliere is this squamous 

 portion of the temporal bone situated ? On the side of the head. And 

 what is the figure of the cranium or skull, and principally that part of it 

 which contains the cerebrum or brain ? It is an elliptical or oval arch. 

 If pressure is made on the crown of that arch — if a blow is received on 

 tlie suture between the parietals siifficient to cavise the elastic materials of 

 wliich the skull is composed to yield — the seat of danger and injury is at 

 the side. If a man receives a ^aolent blow on the crown or back part of 

 the head, the fracture, if there is any, is generally about the temple, and 

 the extravasation of blood is oftenest found there. The following figure 

 will explain this : — 



l2 



