356 THE MECHANICAL FUNCTIONS. 



The horns of the ox and of the antelope tribes are formed 

 of longer and more continuous fibres, which are closely 

 compacted together, and exhibit very distinctly the series 

 of hollow cones of which they are composed. 



The horns of the Rhinoceros, both of the one and two 

 horned species, grow from the integument covering the 

 nose, to which they adhere without having any connexion 

 with the subjacent bones. They have a pyramidal shape, 

 and are composed of parallel fibres, resembling hairs, agglu- 

 tinated together into a solid mass by a material which acts 

 as a cement. This fibrous structure is most distinctly seen 

 at the base of the horn, where the ends of the fibres project, 

 like those of a brush, from the surface. When these horns 

 are sawn transversely, and examined with a magnifying 

 glassy a great number of orifices are seen, marking the 

 empty spaces that intervene between the hairs; and if the 

 section be made in a longitudinal direction, the same spaces 

 give rise to the appearance of parallel grooves. These horns 

 are not deciduous, like those of the stag: but continue to 

 adhere to the skin, and to grow from the root, in proportion 

 as they are worn at the extremity. 



§ 6. Solipeda, 



The Solipeda form a natural family of quadrupeds, in- 

 cluding the Horse, the *dss, the Quagga, the Zebra, &c. 

 which are very nearly allied in their conformation to the 

 ruminant tribe. To combine fleetness w^ith strength has 

 been the obvious design of nature in the construction of 

 these animals. We find, accordingly, that the consolidation 

 of the bones of the foot is carried still farther than in the 

 ruminant tribe; for, in place of the two parallel phalanges, 

 which are, in the latter, articulated with the cannon bone, 

 there is here only a single metatarsal bone. The three pha- 

 langes, of which that single finger consists, bear the names of 

 ihQ pastern, the coronet, and the coffin bo?ie; and the hoof; of 



