B. F. KAUPP. 
C(XJ 
neutrophiles. Three of the protozoa have invaded the muscula¬ 
ture. 
Roup or Avian Diphtheria —This condition is sometimes 
called swelled head, because usually there is swelling about the 
head. 
Cause —The cause appears to be far from settled. American 
and European investigators have from time to time isolated dif¬ 
ferent germs, all of which perhaps contributed to the production 
of conditions found, but there are none of these germs that are 
constantly found by all. With a view of determining whether or 
not the type of roup existing in Colorado is due to an ultra- 
microscopic germ, two diseased hens were secured. These birds 
had swollen eyes, with an accumulation of catarrhal product in 
the maxillary sinuses and a discharge from the nostrils of an 
offensive odor. There were also characteristic yellowish-white 
diphtheritic patches in the mouth. Material from all these lesions 
from both birds was prepared in physiological salt solution and 
filtered through a Pasteur filter, calculated to take out all germs 
that can be seen by aid of the microscope or that could be pro¬ 
duced in visible growth upon artificial media. The fluid that 
passed through this filter was used in inoculation experiments. 
The birds used for this purpose were from flocks in which roup 
had not appeared. In all fifteen inoculations were made. Tubes 
of media were inoculated with the filtrate and no visible growth 
of germs was seen after being incubated at 3 7 degrees Centi¬ 
grade for 72 hours. 
Observations were continued on the inoculated birds for a 
period of thirty days and roup did not appear in any of them. So 
far as this one experiment goes it does not indicate that our type 
of roup is due to a filterable virus. 
Mode of Spread —The disease is spread by the introduction 
of birds from infected premises, and by exposure of birds at 
poultry shows to the contagion. A chronic type of the disease in 
some birds of the flock may serve to infect others, when they 
are weakened by predisposing causes, as by exposure to cold, 
damp roosting places, drafts and badly ventilated buildings. 
Symptoms —There are three forms of the disease. In the 
