THE RESPIRATORY SYSTEM 135 
Rhinitis, Sinusitis. 
The nature of mflammations of the nasopharynx sug- 
gests at once that there may be some anatomical reason 
for their distribution and character. A general review of 
the anatomy of the mammalian and avian nasopharynx 
reveals the relatively greater space in the former, espe- 
cially in the passage from the nose to the pharynx, and 
emphasizes the exposure of the opening of the upper 
larynx in the bird, lying as it does in the posterior part of 
the tongue and surrounded by the constrictores glottidis. 
A dissection of the accessory nasal sinuses exposes the 
relatively large size of these spaces in the lower mammals, 
and the capacious openings into the nasal cavities. (1) In 
the Primates and Lemures the anatomy more closely 
resembles that of man, the sinuses being relatively smaller 
and the communicating passages narrower. In the bird 
on the other hand, while the sinuses may be extensive in 
some they are usually small, yet in all the communication 
with the turbinate area is by a narrower slit or tortuous 
canal, frequently, as in Galli, running from below upward 
into the maxillary sinuses. The extent of the turbinate 
and the richness in mucosa is probably greater in all 
mammals than in birds; certainly this seems true of 
Carnivora and Ungulata versus Accipitres and Galli. 
If the seriousness of a rhinitis be dependent upon the 
extent of involvement of the sinuses and the blocking up 
of their outlets it would be expected that the variety of 
animal having the smallest drainage channels would show 
the greatest evidence of these diseases. Our records 
would indicate that 32 birds (.96 per cent, of the autopsies 
upon Aves) had rhinitis whereas only 7 mammals (.39 
per cent, of autopsies on this class) presented the con- 
dition. Extension to the sinuses occurred in only one- 
third of each of these figures, a complication which 
in turn produced generalized infection more often in 
(1) Vide Sisson's Veterinary Anatomy and Owen's Anatomy of 
the Vertebrates. 
