CONGENITAL MALFOBMATIONS 307 



Teeth. 



What congenital malformations of the jaws and teeth are of 

 interest to the surgeon ? 



Quite common are supernumerary teeth, also tusks in 

 canines and mares. By prognathia swperior is understood an 

 upper jaw which, exceeds in length the lower jaw, commonly 

 feown as an overshot jaw; by hrachygnathia inferior is. 

 understood a lower jaw which is too short. The opposite 

 condition — that is, an undershot jaw — simply reverses- 

 matters. 



Intestines. 



In what animals are congenital malformations of the intestine- 

 observed f 

 In pigs, colts, puppies, in the shape of a hernia ; another 

 ifiaKormation, which is hy no means rare, is partial or com- 

 plete obliteration of the anus and rectum, known as atresia^ 

 ami and atresia recti respectively. 



Bye. 



What are dermoid twmors ? 



Small, skin-like, hairy growths at the margin of the cor- 

 nea, most frequently seen in dogs and calves, but ^./ccasionally 

 also in other animals. 

 What other congenital malformations are observed ? 



Paralysis of the optic nerve ending, known as amaurosis,, 

 cataracts; in horses, excessive development of the soot balls, 

 congenital fissure of the iris, termed coloboma, closure of the 

 inferior opening of the lachrymal canal ; in puppies, congen- 

 ital closure of the palpabral fissure ; in dogs and colts, con- 

 genital atrophy of the eye, known as miorophthalmus. 



