DISEASES OF THE BLOOD VESSELS 77 
the other case a vegetative growth occurred on the intima 
near the dilatation. 
The Picariae were represented by a Hornbill and a 
Toucan. The former presented roughened yellowish ele- 
vations for two centimetres above the aortic valve ; this 
seemed the only involvement. The Toucan had a 
few small scattered but deep yellow plaques in the 
same location. 
Psittaci, although failing to be accredited with a high 
percentage of arterial disease, nevertheless present some 
striking and interesting changes. In the first place, the 
central vessels are not so conspicuously the principal seat 
of atheroma as is the case in many other orders, and the 
lesions are not so productive. It is usual to find flat areas 
of opacity, perceptible as easily by section through the 
wall as by holding up the opened vessel to the light, 
the seat of the density being in the media. This can be 
followed into the wing arteries and, upon microscopic 
section, these smaller vessels will show mesial degener- 
ation, thus being comparable to arteriocapillary fibrosis 
of man. However frequent this picture may be, there are 
also instances of overgrowth in the intima, prominences 
over opacities or raised plaques at the points of branching, 
lesions which correspond to the activity of the inner coat. 
It is interesting that renal disease, chronic pulmonary 
and general infections occur in a goodly proportion of 
these birds. 
Striges is an order of little importance. The lesions 
in the two cases consisted of rather prominent plaques in 
aorta and large branches. 
Accipitres stand out as giving the greatest percentage 
of any order of which we have had a fair number upon 
which to make comparisons. Their arterial lesions are 
frequently accompanied by renal, myocardial and valvu- 
lar disease. Mesial and intimal alterations are about 
equal in degree, irregular patches going on to softening 
without ulceration, and early calcification being quite 
prominent. The sickle at the branching of the renals is a 
