150 



THE AUSTRALIAN MUSEUM MAGAZINE. 



A Horse s Hardship. 



By E. le G. Troughtox. 



I 



An important feature of museum work 

 consists in identifying and supplying in- 

 formation concerning specimens sent from 

 all parts ©f the State or brought in per- 

 sonally. These si>ecimens are sometimes 

 of great interest, not only to the en- 

 quirer but also from a scientific point of 

 view, and there is always a chanc* that 

 the bringing in of some unusual type of 

 animal may lead to an important dis- 

 covery. 



Occasionally a specimen is abnormal in 

 some way, perhaps a monstrosity like a 

 two-headed calf or, as a specimen does 

 not necessarily represent an entire crea- 

 ture, it may be a single vertebra of an 

 extinct gigantic lizard or the small tooth 

 of some native animal; again it may be 

 a bone deformed owing to an accident, as 

 is the object described in this note. 



The accompanying illustration shows 

 the metatarsal or "cannon bone" of the 

 hind-limb of a horse from Graham's Val- 

 ley, near Glen Innes, New South Wales, 

 brought in recently by Mr. C. E. Watson. 

 Round the bone is looped a piece of or- 

 dinary strong fencing wire, the ends of 

 which are twisted firmly together. The 

 movement of this loop has worn a groove 

 in the bone which is accentuated by a high 

 ridge of callus on either side of it. Such 

 an irritation of living bone would excite 

 a prolific flow of constructive matter from 

 the cells, and in this way are deposited 

 new layers, emanating from the bone it- 

 self, which would soon cover an immov- 

 able body of limited size. Indeed, it has 

 been proved that if the surface of a bone 

 is removed and a close-fitting silver ring 

 placed round it, living bone will surround 

 and cover the ring. In one operation a 

 silver ring, placed round a bone denuded 

 of its outer membrane, had in three 

 months been completely enveloped in 

 newly formed bone an eighth of an inch 

 thick. 



In this case the limiting membrane, or 

 periosteum, which controls the growth has 



been worn through and, as the groove be-j 

 came deeper, the growing shaft of bonej 

 has thrown out new layers in an eifort to 

 bridge the interspace. The painful move- 

 ment of the wire, however, has kept the 



"Cannon," or Metatarsal bone of horse. 

 Phorto — G. C. Glutton. 



limiting membrane incomplete, and, with- 

 out its controlling influence, an overflow 

 of gi-owing tissue has banked up on either 

 side of the groove. Unfortunately, though 



