50 



HORSES. 



Chap. II. 



Of individual variations not known to characterise particular 

 breeds, and not great or injurious enough to be called mon- 

 strosities, I have not collected many cases. Mr. Q. Brown, of 

 the Cirencester Agricultural College, who has particularly 

 attended to the dentition of our domestic animals, writes to 

 me that he has " several times noticed eight permanent incisors 

 instead of six in the jaw." Male horses alone properly have 

 canines, but they are occasionally found in the mare, though 

 of small size. 4 The number of ribs is properly eighteen, but 

 Youatt 5 asserts that not unfrequently there are nineteen on 

 each side, the additional one being always the posterior rib. 

 I have seen several notices of variations in the bones of the leg; 

 thus Mr. Price 6 speaks of an additional bone in the hock, and of 

 certain abnormal appearances between the tibia and astragalus, 

 as quite common in Irish horses, and not due to disease. Horses 

 have often been observed, according to M. Gaudry, 7 to possess 

 a trapezium and a rudiment of a fifth metacarpal bone, so that 

 " one sees appearing by monstrosity, in the foot of the horse, 

 structures which normally exist in the foot of the Hipparion," 

 — an allied and extinct animal. In various countries horn-like 

 projections have been observed on the frontal bones of the 

 horse : in one case described by Mr. Percival they arose about 

 two inches above the orbital processes, and were " very like those 

 in a calf from five to six months old," being from half to three- 

 quarters of an inch in length. 8 Azara has described two cases 

 in South America in which the projections were between three 

 and four inches in length : other instances have occurred in 

 Spain. 



That there has been much inherited variation in the horse 

 cannot be doubted, when we reflect on the number of the breeds 

 existing throughout the world or even within the same country, 

 and when we know that they have largely increased in number 



4 ' The Horse,' &c, by John Law- 

 rence, 1829, p. 14. 



5 ' The Veterinary,' London, vol. v. 

 p. 543. 



6 Proc. Veterinary Assoc, in ' The 

 Veterinary,' vol. xiii. p. 42. 



7 « Bulletin de la Soc. Geolog.,' torn, 

 xxii., 1866, p. 22. 



8 Mr. Percival, of the Enniskillen 

 Dragoons, in ' The Veterinary,' vol. i. 

 p. 224 : see Azara, ' Des Quadruped.es 

 du Paraguay,' torn. ii. p. 313. The 

 French translator of Azara refers to 

 other cases mentioned by Huzard as 

 occurring in Spain. 



