IMMUNIZATION WITH BACTERIOPHAGE SUSPENSIONS 513 



a poultry-yard containing about 100 fowls where typhosis had appeared. 

 These 20 were immunized with a suspension of Gallinarum-bacterio- 

 phage. On February 7 the immunized birds were all ahve and in 

 perfect condition, while the epizootic had continued to spread among 

 the non-immunized animals, of which only about 20 remained. 



Barnyard 2. On February 23 the surviving chickens of a poultry- 

 yard containing at that time 102 animals were immunized. The 

 epizootic which began about 10 days previously, and which had resulted 

 in a daily mortahty of 4 or 5 chickens, stopped quickly and perma- 

 nently from the time of the immunization. The epizootic continued, 

 on the contrary, to ravage with the same intensity as formerly in all 

 the neighboring poultry-yards which served as controls. 



Experiment III. This experiment was conducted at Provins, with 

 the aid of M. Sorriau, D.V.M., in an important poultry-yard where 

 typhosis was present in endemic form. 



For several months the daily mortality had been 2 or 3 fowls. On 

 January 25 the 225 survivors were immunized. The epizootic im- 

 mediately and permanently disappeared from the date of the immuni- 

 zation. 



Experiment IV. Performed at Rouillac, Charente, with the assist- 

 ance of M. Chollet, D.V.M. 



On December 15, 100 fowls were immunized in a poultry-yard where 

 typhosis had appeared about ten days previously. The daily mor- 

 tahty had been from 4 to 6 animals. With the immunization there 

 was an immediate and permanent cessation of the epizootic. Typhosis 

 continued to prevail on all the neighboring farms. Among the 100 

 chickens inoculated, about 12 were already affected. Of these only 

 2 died, 2 and 3 hours after the injection. 



Experiment V. This test was conducted with the assistance of Dr. 

 Ormieres at Carcassonne. 



The epizootic began during the month of August. By October 1, 

 80 chickens had succumbed. The 120 survivors were immunized. 

 The epizootic stopped immediately and no further cases appeared after 

 the date of the immunization. 



Experiment VI. This experiment was conducted with the assistance 

 of M. Mesnard, Departmental Veterinarian at Angouleme. In these 

 experiments the chickens were immunized by the ingestion, on bread, 

 of about 1 cc. of a Gallinarum-bacteriophage. 



A. On July 2 the 50 chickens surviving in a poultry-yard where 

 typhosis had been prevalent for six weeks, with a daily mortality of 



