42 Vniversihj of California Publications in Zoology [Vol. 11 



Development of Roup in Immune Fowls. — On the same day 

 in which the ten normal fowls were inoculated with the Hawaiian 

 virus, ten hyper-immune fowls were inoculated with the same 

 virus. These immune fowls developed no lesion of epithelioma 

 eontagiosum at any time. However, the normal ones developed 

 typical growths of epithelioma eontagiosum at the seat of inocu- 

 lation, in the usual time, and a few days later three of them 

 developed typical sypmtoms of roup. There was profuse puru- 

 lent discharge from the nose and mouth, the sinuses under the 

 eyes became greatly enlarged, the eyes were swollen, closed and 

 filled with cheesy, white exudate, the fowls refused food, became 

 moribund and died. Within a short time another developed the 

 same symptoms and at the same time two of the immime group, 

 which had given no evidence of epithelioma eontagiosum after 

 repeated inoculations, succumbed with typical .symptoms of roup. 

 The remainder of those inoculated with the Hawaiian virus 

 recovered in the usual way, without showing any signs of roup. 

 However, since Ward (1905) has shown how difficult it is to 

 transmit roup by inoculation (only one of seventeen being posi- 

 tive in his series), its absence from some of the members of the 

 later group would .seem to have no bearing on our conclusions. 

 Our results point rather strongly to the conclusion that we had 

 one strain of the virus of epithelioma eontagiosum which was free 

 from roup, and one which wa-s mixed with the virus of roup. 

 Because of our results, we are led to believe that Schmid and 

 others who have apparently obtained both diseases with a single 

 virue, had a mixture of the causative agents of two entirely 

 separate diseases. 



POSSIBILITY OF DOUBLE INOCULATION 



That the virus of epithelioma eontagiosum in the form of 

 the scabs is capable of carrying a second infective agent, is shown 

 by a small series of inoculations we carried out in 1910. Two 

 of the cockerels used had slight purulent discharges from the 

 nostrils, having what is usually termed a cold. These cockerels 

 were inoculated with epithelioma eontagiosum and later material 

 was taken from them and four other cockerels inoculated. Each 



