48 THE HEAD. 



deposited in its stead. In flat bones, like those of the head, thib 

 deposit takjjs place in the centre, and rays or radiations of bone 

 extend thence in every direction. Then, by having so many 

 bones, there are so many centres of radiation ; and, consequently, 

 the formation of bone is carried on so much the more rapidly, and 

 perfected at the time when the necessities of the animal require 

 it. At the period of birth, however, this process is not completed, 

 out the edges of the bones remain somewhat soft and pliant, and 

 therefore, in parturition, they yield a little and overlap each other, 

 Rnd thus, by rendering the birth more easy, they save the mother 

 much pain, and contribute to the safety of the foal. 



The frontal bones are united by a curious and intricate dove- 

 tailing to defend from injury the brain which lies beneath the 

 upper part of thera. Lower down, and where the cavity of the 

 nose is only to be defended, their union is sufficient, but far less 

 complicated. Here we have a proof of wise design. 



Few things more clearly indicate the breed or blood of the 

 horse thon the form of the frontal bones. Who has not remarked 

 the broaa angular forehead of the blood horse, giving him a 

 beautiful expression of intelligence and fire, and the face gradu- 

 , Uy tapering from the forehead to the muzzle, contrasted with 

 the large face of the cart or dray-horse, and the forehead scarcely 

 wider than the face ? 



At/", between the frontal bones, is the pit or cavity above the 

 eye, and by the depth of which we form some idea of the age of 

 the horse. There is placed at the back of the eye, a consider- 

 able quantity of fatty substance, on which it may revolve easily 

 and without friction. In aged horses, and in diseases attended 

 with general loss of condition, much of this disappears ; the eye 

 oecomes sunken, and the pit above it deepens. 



The sinuses oil the different sides of the forehead do not commu- 

 icate with each other, but with other sinuses in the ethmoid, 

 ind sphenoid, and upper jaw-bones, and also with the cavities of 

 \he nose on their respective sides. These sinuses afford a some- 

 vhat increased protection to the brain beneath ; and by the con- 

 tinuous and slightly projecting line which they form, they give 

 beauty to the forehead ; but their principal use probably is, like 

 the windings of the French horn, to increase the clearness and 

 loudness of the neighing. It will be remarked that they are very 

 irregular in depth, which at one place is an inch or more. 



In the sheep, and occasionally in the ox — rarely in the horse — 

 the larvEB of maggots, produced by certain species of flies, crawl- 

 up the nose, lodge themselves in these sinuses, and produce intol- 

 erable pain. 



Veterinary surgeons have availed themselves of these smuses 

 to detect the exister"" "^ fTior«?oro in /Imyiitfiii mopk. Tf thn 



