208 



TECHNICAL BULLETIN 14. 



Seven of the birds were given a dose of the triple strength vaccine in order 

 to make the immunity more intense, if such a thing were possible. The sera 

 were tested both undiluted and diluted. Normal fowl serum was used as a 

 control. All tubes were placed in a water bath at 37..5° C. for one hour and 

 tiiereafter placed in the incubator over night. 



Table 2. Protocol of precipitin test. 

 Rack No. 1 



Tube 1. Anti-pox serum 



Tubo 2. Normal serum 



Tubo 3. Anti-pox serum 



Tubo 4. Saline 



0.5 cc. + 1 cc. virus filtrate. 



0.5 cc. + 1 cc. virus filtrate (control). 



0.5 cc. -|- 1 cc. saline (control). 



0.5 cc. -j- 1 cc. virus filtrate (control). 



Rack No. 2 



Tube 1. 0.2 cc. serum (undiluted) 



Tube 2. 0.2 cc. serum (1-5 dilution) 



Tube 3. 0.2 cc. serum (1-10 dilution) 



lube 4. 0.2 cc. serum (normal) 



Tube 5. 0.2 cc. serum undiluted 



Tube 6. 0.2 cc. saline 



+ 0.2 cc. virus filtrate. 



+ 0.2 cc. virus filtrate. 



+ 0.2 cc. virus filtrate. 



+ 0.2 cc. virus filtrate (control). 



+ 0.2 cc. saline (control). 



+ 0.2 cc. virus filtrate (control). 



Results: 



In no case was there any evidence of a })recipitin reactit)n. 



Passive Immunity. 



Eight Rhode Island Red cockerels were divided into two groups of four 

 birds each. Each bird received three injections of "immune" serum in the 

 manner siiown below in Table 3. The serum was obtained from immune birds 

 tliat had demonstrated a three-plus complement-fixation reaction of their sera 

 at various times. The sera were collected and pooled for injection on the 

 same day that they were administered. 



TABLE 3 — Degree of protection afforded by the intravenous and subcutaneous injection 



of "immune" serum 



-t- First evidence of pox nodules, immature and sparse. 

 -|- -t- Appearance of a few or several well formed pox nodules. 

 + + -1- .\ppearance of many pox nodules of mature development. 

 4--|--f- + Maximum development of pox nodules. 

 - Negative. 



