No evidence of tumor or other neoplasm or pathological condition 

 could be found to explain the roaring, except that it was found 

 that the right nostril was impervious to air and that a flexible 

 sound could not be passed into the pharynx through the right 

 nasal passage. Failing, like me, to make a diagnosis, the filly was 

 destroyed, and, as in our own case, the autopsy revealed a thin 

 septum stretched across and completely closing the right posterior 

 naris, and, in full accord with our views in this case, he considered 

 the cause an arrest in development in the early embryonic stage, 

 by which the septum, at that time normal, failed to undergo that 

 obliteration which should naturally follow. 



Perhaps the deformity is more common than records would indi- 

 cate, and it would seem not unlikely that in some cases both septa 

 persist, leading, especially in foals, to early death, owing to the 

 difficulty it has in breathing through the moutli ; hence it would 

 seem well for veterinarians to have in mind the possibility cf the 

 occurrence of this peculiar form of arrested development, its diag- 

 nosis and treatment. 



The diafj)iosk offers no great difficulty to the veterinarian cog- 

 nizant of the occurrence of such an abnormality. We observe : 



a. Dyspno?a and roaring. 



b. Imperviousuess of the affected passage to air. 



c. The absence of any neoplasm or tumors in the nasal passages 

 or sinuses, or of dental or other diseases leading to suppuration or 

 other changes capable of interfering with respiration. 



d. The nasal passage and nostril free ; though, perhaps owing to 

 non-use, the turbinate bones are nearer to the nasal septum than 

 ordinarily observed. 



e. The posterior naris closed, as shown by the impossibility of 

 passing a sound into the pharynx, but permitting the sound to pass 

 over the naris until the ethmoid bone is reached. 



f. The Polansky-Schindelka rhino-laryngoscope would enable 

 one to observe tlie actual condition of the deformed part. 



The Gunther Eustachian catheter should prove an excellent 

 sounding instrument, or in its absence an effective sound of similar 

 form could be improvised — that is, a rod about one-fourth of an 

 inch in diameter, with a slight curve anteriorly, commencing about 

 two inches from the anterior end. With this sound measure the 

 distance from the superior angle of the nostril to the lachrymal 

 angle of the orbit, which will about equal the distance from the 

 inner border of the nostril to the centre of the posterior naris. 



Passing the sound along the floor of the nasal chamber, it will 



