68 CLASS MAMMALIA. 



stricted, in all probability, to those species which reside in 

 cold and temperate regions, or who have these productions 

 of a large size. It is the opinion of Sir T. S. Raffles that 

 the Muntjaks of the Indian Archipelago never, or at least 

 but seldom, renew theirs ; and our own researches within 

 the tropics of America tend to confirm it, so far as relates 

 to that class of them who have only single spikes, and 

 branched antlers. 



Animals offer few phenomena more inexplicable than 

 that species of vegetative spontaneous production, of which 

 the germ is invisible, and which, nevertheless, is subordi- 

 nate to fixed and precise laws. At a given age the horns 

 of the deer-kind begin to develope ; at first a slight protu- 

 berance appears, covered by the skin, where a great num- 

 ber of vessels are spread, for a considerable degree of heat 

 is perceptible under it. Soon the protuberance rises, 

 and in some species branches off into ramifications ; after 

 a certain period the development is arrested, the skin 

 which had continued to stretch and extend over the whole 

 production, loses its heat, dies, becomes dry, and finishes 

 by tearing off in rags ; at length the horn itself becomes 

 detached and falls ; a slight hemorrhage follows from the 

 skin or the part of the frontal which sustained it. After 

 twenty-four hours in healthy Deer, the vessels which emitted 

 the blood are closed, a thin pellicle covers the wound, and 

 immediately the reproduction of a new horn becomes ap- 

 parent; the extremity of the vessels swells, a burr expands 

 around the base where the late horn stood, resembling 

 those on the bark of trees, when they have received wounds 

 which begin to cicatrize : the burr widens, while the ves- 

 sels which proceed from the bone depose osseous matter 

 Hitherto the development of the horn has been uniform, 

 the vessels have extended in a certain direction, always the 

 same in each species ; but when they have arrived at a 

 certain point, they separate, some continuing as before, 



