92 RUMINATING ANIMALS. 



only last for a season, the different stages of their 

 formation can be readily traced ; and when they are 

 completed, and the supply of blood is withdrawn, the 

 process of exfoliation, by means of which they drop 

 off, is a beautiful illustration of that operation. 



In their growth, the first change that takes place, 

 is a very considerable enlargement of the arteries 

 leading to that part of the skull ; then the horn, as 

 it is termed, begins to shoot. In the early stages, 

 it is a vascular cartilaginous structure, covered with 

 a velvet-like cutaneous covering. The cartilage is 

 gradually converted into bone ; and when this pro- 

 cess is completed, the covering becomes so thin, 

 that it is readily rubbed off by friction in the use of 

 the horn. 



" As soon as the horns become hard, the blood- 

 vessels going to them gradually diminish in size till 

 the horns are deprived of all support, after which 

 they are exfoliated like any other dead bone. This 

 is perhaps the most beautiful instance in nature, of 

 a bone being formed for a temporary use, and cut 

 off by absorption, as soon as the purpose is answered 

 for which it was intended : the use of the velvet-like 

 covering is evident, as it corresponds to the perios- 

 teum of other bones, being the medium through 

 which the nourishment is received ; and as soon as 

 that is separated, in both cases death takes place. 



" That this weapon of defence in the male of the 

 deer kind should owe its growth, and its decay, to 

 the state of the organs of generation, is a very ex- 



