450 THE MECHANK AL FUNCTIONS. 



the violent strains and concussions they ninst be 

 exposed to in these quick and jarring efforts, is 

 truly wonderful. 



While Nature has provided these animals with 

 the means of safety from their more formidable 

 enemies, she has not left them altogether without 

 defence against their more equal rivals in the field. 

 It is on the head that she has implanted those 

 powerful arms which are sometimes wielded with 

 deadly effect in their mutual combats. Even when 

 not furnished with horns, the animal instinctively 

 strikes with its forehead, where the frontal bone 

 has been expanded and fortified, apparently with 

 a view to this mode of attack. Thus, the ram butts 

 with its head without reference to the horns, which 

 are coiled so as to be turned away from the object 

 to be struck. In the Deer and the Ox tribes, 

 however, the horns are formidable weapons of 

 offence: and it will be interesting to inquire into 

 the nature of these organs, and the phenomena of 

 their production. 



The antlers of the male Stag are osseous struc- 

 tures, supported on short and solid tubercles of the 

 frontal bone : after remaining nearly a year, they 

 are cast off, and soon replaced by a newly formed 

 antler, which is of larger size than the one that 

 was lost. Previously to the formation of this struc- 

 ture, those branches of the artery, termed the caro- 

 tid, which supply blood to the frontal bone, are 

 observed very rapidly to dilate, and to throb with 

 unusual force ; and all the blood-vessels of the skin 

 of the part where the antler is to arise, soon become 

 distended with blood, an effect which is accompa- 

 nied by general heat and redness, like a part in a 



