1913] Siirrf: Epithelioma of the Common Fowl 35 



MUelncss of Inoculated Disease. — In a series of over fifty in- 

 oculations, where the virus was unmixed with roup, no fatal ter- 

 minations were seen except in two cases, in which the vitality 

 was greatly lowered by excessive bleeding. These two fowls be- 

 came moribund and were killed. At autopsy the internal organs 

 were normal as were the mucous membranes of the head and 

 throat. Cultures taken from the depths of the growths on the 

 comb and from the ventricles of the heart, gave a growth of 

 an organism that was probably Staphylococcus albus. This would 

 sugge.st that death was due to a terminal infection, the portal of 

 entry being the lesions on the head. These findings conflict with 

 those of Reisehauer (1906), who found the heart blood sterile in 

 a considerable number of cases, and are too few in mmiber to 

 be more than .suggestive. "With the exception of these two cases, 

 at no time during the course of the disease were the fowls very 

 much disturbed, as they continued to take food and in every other 

 way to act normally. As Gary (1906) and others have pointed 

 out, the disease is not often fatal except in young fowls. The 

 fowls we used were for the most part nearly grown. However, 

 our records lead us to believe that the disease is a much milder 

 one than roup and that much of the mortality which has been 

 attributed to it may be due to the simultaneous occurrence of the 

 two diseases. Of course, it is also possible that our percentage 

 of mortality was lowered by the virus used (although several were 

 used) being less active than that used by others, or it may be 

 that the climate at Berkeley is unfavorable to the development of 

 the disease. The fact that a number of strains of virus were 

 used would render the first supposition improbable and we can 

 hardly believe too great weight should be given the latter factor. 



Epidemiology. — Epithelioma contagiosum is evidently con- 

 tracted directly. Burnet (1906) has shown that it can be con- 

 tracted by ingestion of the virus, that the virus is present in 

 the blood stream, and that the typical disease can be produced 

 by intravenous injection. We have confirmed his experiments 

 showing the virus to be present in the blood stream, by injecting 

 blood from a diseased fowl into a normal fowl, and thereby 

 producing specific lesions, not only on the mucous membranes, 

 but also at the usual sites on the comb and wattles. "We are 



