THE URINARY TRACT 281 
the thoracic areolar tissues, but is only exceptionally per- 
ceptible before the body is opened. Anemia is almost 
never extreme. The bone marrow although mentioned in 
but few histories, seems unchanged. Cardiac hypertrophy 
was observed ten times in 652 cases of nephritis, twice in 
460 acute and subacute cases, eight in 192 chronic cases. 
In the former no myocarditis was found, in six of the 
latter it was found. Clinical and pathological experience 
teaches that serous surfaces are frequently inflamed 
during a nephritis. Observations on our material coincide 
with this statement, but do not offer an explanation of it. 
The figures should be examined for mammals and for 
birds separately, since the serous cavities of the former 
are closed, separated, and protected, whereas a close 
apposition exists between the serous membranes and the 
lungs in birds, an arrangement facilitating infection from 
without. Nevertheless the bird has definitely less sero- 
sitis accompanying nephritis than does the mammal — 
4.4 per cent., versus 8.6 per cent. In the former class 
70 per cent, of these accompany acute nephritis associ- 
ated with acute general disease while only 45 per cent, of 
the 8.6 per cent, of mammals had serositis, acute 
nephritis and general infection. This indicates clearly 
that mammalian renal disease has some effect upon serous 
membranes other than the simple participating coinci- 
dence of the two types of changes during an acute general 
infectious disease. No one kind of nephritis was espe- 
cially characterized by this complication. 
Uremia, except under the best clinical conditions, is a 
term to use with caution. I have seen several monkeys, 
a few marsupials and carnivores and an occasional bird 
in a dazed ataxic condition, sometimes exhibiting an 
atypical clonic or tonic convulsion, with fixed, rather 
small pupils. To this picture I have applied the name 
uremia, and upon several occasions have found a severe 
grade of nephritis. I must admit having failed to find 
renal change, however, with this clinical picture, espe- 
19 
