172 DISEASE IN WILD MAMMALS AND BIRDS 
passed on to the gizzard. The organ has a rather free 
position, at least as far as its left lateral and do^vnward 
movements are concerned for the left lateral abdominal 
air sac is free on that side of the gastric complex and the 
left lateral thoracic also extends do^\Ti the side of the 
proventricle. Upward and anteriorly is the heart. Some 
of the cases of proventricular spiropteriasis have shown 
very marked congestion of the left lung, possibly due to 
the closure of the anteroinferior air sac aperture on that 
side. Aside from parasitism, affections of this organ are 
not very numerous. 
Infestation with spiroptera and mth less dangerous 
worms Avas quite serious at one time, but since routine 
examinations of all suspicious birds has been practiced 
this parasitism has been under control. This is a subject 
of especial importance to collections, and will be described 
in a special section. The susceptibility of the proventricle 
to damage seems from our figures to be very distinctly a 
matter of zoological order. In so far as parasites are 
concerned, the parrot group stands away ahead of all 
others having an incidence among autopsies upon Psittaci 
of 16 per cent. ; after them come the PicarisB with 9 per 
cent., and Columbae and Passeres each with 4 per cent. 
AVhen, however, non-verminous conditions are reviewed 
the anserine birds are found the most susceptible, 3 per 
cent, of the autopsies upon this order revealing proven- 
tricular lesions; after them come the Columbse, 2 per 
cent., and Psittaci, 1.5 per cent. In this group are 
included inflammations of all kinds, dilatations and dis- 
tentions and some lesser matters. 
This part of the stomach has been involved in our cases 
of fowl diphtheria, showing a distinct mucopurulent 
inflammation with penetration into the depths of the 
glands ; no separation of the mucosa occurred, but ulcera- 
tion was seen. Perforation w^as observed thrice, twice by 
ulceration around a worm while it was boring into the 
