CUTANEOUS VACCINE FOR FOWL POX 245 



Weight and rectal temperatures were recorded daily between 10 A. M. 

 and 12 M. during the extent of the three experiments described. For the 

 purpose of comparison the readings of the three experiments are grouped 

 together in Table 1. The minimum and maximum temperatures and weights 

 are recorded for each of the three stages of each experiment. The pre- 

 liminary stage represents the period during which readings were taken in 

 order to determine the normaJ rectal temperature and increase in body 

 weight. It covers the time from the beginning of the experiments to the 

 day of vaccination. The stage of infection is that period of time from the 

 day on which the birds were vaccinated to thd day on which the scabs had 

 entirely disappeared from the va,ccinated area. The stage of recovery is 

 that period of time during which the birds would natturally return to normal 

 if there were a deviation from the normal during the stage of infection. 



All birds in these experiments were confined to individual experimenital 

 cages. The birds in experiment 1 were hopper-fed whole yellow corn and 

 a commercial laying mash. This ration was supplemented with 1 per cent 

 cod liver oil, and cabbage was fed twice weekly. Those in experiment 2 

 were fed intermediate scratch feed and a growing mash in hoppers, sup- 

 plemented with 1 per cent cod liver oil. In experiment 3 the birds were first 

 fed a mixture of two-thirds growing mash and one-third fine scratch feed 

 with 1 per cent cod liver oil until 100 days old, and later growing miash 

 and intermediate scratch feed ad libitum in separate hoppers, 1 per cent 

 cod liver oil bein'g mixed with the mash. 



Oroup 1. 



Ten White Leghorn cockerels, approximately 210 days of age, were used 

 in this experiment. Six of the birds were vaccinated cutaneously with the 

 standard vaccine containing 200 mgm. of virus in 50 cc. of 40 per cent 

 glycerol-physiological saline solution. The remaining four birds were used 

 as unvaccinated coiitrols. Forty days after vaccination the comibs of tlie 

 entire group were scarified and inociilated with a heavy suspension of fowl 

 pox virus in order to determine if immunity against the disease had de- 

 veloped. No lesions appeared as a result of the inoculation in the vac- 

 cinated birds. The unvaccinated controls showed from a moderate to a 

 severe type of infection as a result of the inoculation. The vaccination had 

 caused the development of a complete protection (cutaneous immunity) 

 against the disease. 



Oroup 2. 



Thirty Rhode Island Red puUets and cockerels of the same strain and 

 hatch were used in this experiment, twenty-four being vaccinated and six 

 left unvaccinated as controls. They were 80 days old on the day they were, 

 vaccinated. Three different vaccines were used in this experiment; one, a 

 widely distributed commercial cutaneous vaccine; the second, the standard 

 200 mgm. vaccine; and the third, a vaccine identically the same as the stand- 

 ard vaccine except that it contained but one-half as much virus, or 100 mgau 



When vaccinating birds so young, it was; necessary to exercise unusual 

 precautions. In many cases the feather follicles were so small that it was 



