444 BENIGN TUMOURS. 



The first form is found in animals during the active period 

 of dentition — from one to three years old — and is recognised 

 by a gradual enlargement of one or both sides of the face, 

 usually of one side only, with a discharge from the nostril of 

 an albuminous fluid of the consistence of synovia, which 

 gradually changes into a purulent matter streaked with blood. 

 There is a snuffling sound in the breathing, as if the nasal 

 cavity w^ere diminished in calibre ; and this, as well as the 

 swelling and discharge, increases — sometimes very rapidly, at 

 other time more slowly, until at last the animal has to be 

 destroyed. 



There is no cough, or if there be, it is only accidental, and 

 the animal usually feeds well and thrives moderately. 



On making a post-mortem examination the superior maxillary 

 sinus will be found to contain a rounded mass (made up of 

 numerous cells, containing a glairy fluid), pressing upon the 

 nasal borders and turbinated bones, causing them to bulge into 

 the nasal cavity, diminishing its calibre, producing a difficulty in 

 breathing, and a snuffling sound during the egress and ingress of 

 the air. 



Upon trephining a case of this kind, it will be discovered that 

 the sinus contains a glairy fluid, and a friable and highly vascu- 

 lar mass, which forms the walls of the cysts, having a structure 

 similar to that of the turbinated bones. Whether it is an extra- 

 ordinary development of the sinus before the bones of the face 

 are sufficiently large to accommodate it, or whether it is a new 

 formation — a cyst — I can scarcely determine ; but whatever it 

 may be, it can be removed by an operation if it has not been 

 allowed to go on too long. The method of operation is as fol- 

 lows : — Make an incision through the skin about four inches 

 long, and dissect it upwards as a flap ; trephine the face, near 

 the junction of the nasal and superior maxillary bones of the side 

 affected, in two places, about three inches apart ; and with the 

 bone forceps remove the bone between the two apertures, making 

 the gap about an inch in width, then with a hook and sharp 

 scalpel dissect the whole of the sac away, taking care not to 

 disturb the young teeth. If it be found that the turbinated 

 bones have been pressed into the nasal cavity, a portion of them 

 may be removed also. After washing out the debris of the sac 

 and clots of blood, bring the skin to its proper position, and 



