168 DISEASE IN WILD MAMMALS AND BIRDS 
Phakynx. 
The buccal-pharyngeal cavity in mammals is used 
chiefly as a passage way for food and as the place where 
some of them triturate and insalivate the bolus. Certain 
orders, Primates, rodents and marsupials, use this cavity 
thoroughly at the first mastication, others use it little at 
first but may ruminate, the ungulates, while strict car- 
nivores use it very little. The Aves use their pharynx 
almost exclusively as a passage, and, despite the presence 
of a certain amount of salivary gland tissue, probably do 
not digest any substance in this cavity. The crop or 
ingluvies is a sac to permit of salivary digestion but is 
really a storehouse to allow rapid feeding without over- 
filhng of the proventricle. The esophagus extends from 
the pharynx to the cardiac opening of the stomach in 
mammals and widens into the glandular stomach or 
proventricle in birds, the upper end of which lies in front 
of the lower third of the left lung beliind the heart. 
Inflammations of the buccal, pharyngeal and esopha- 
geal walls are relatively common in certain orders espe- 
cially ground birds and grazing ungulates. This would 
seem to be explained on the basis of injury to the mucosa 
by sharp or pointed objects picked up while feeding. The 
character is usually necrotizing, but need not be, and the 
bacteriology is not specific. Definite infectious diseases 
like diphtheria and actinomycosis are not included here, 
but it might be mentioned that the second disease cited 
is believed to be started by the penetration of the organ- 
isms into wounds made by sharp grasses. Certain orders, 
notably Ungulata, Passeres, Psittaci and Struthiones, are 
quite susceptible to mycotic infestation and we have seen 
an outbreak of thrush in Kites (Accipitres). It is, how- 
ever, interesting and possibly significant of peculiar 
protective powers in the upper alimentary tract, that 
strict carnivores have failed to show ulcerative, purulent 
or necrotizing inflammations of the mucosa from the 
