150 The Philippine Journal of Science 1915 
thoroughly mixed with 30 cubic centimeters of a 5 per cent 
glycerin agar made somewhat stiffer than usual. The culture 
had grown on 5 per cent glycerin agar to which a few drops 
of sterile unheated human serum had been added, and showed an 
abundant growth. Three cubic centimeters of this mixture were 
given to all animals except one, which received 2.25 cubic centi- 
meters. The second group, “Tbag hb,” received the same agar 
mixture as the first group, except that the proportion of bacilli 
in the agar was doubled. 
The third and fourth groups include animals which received 
emulsions of bacilli without agar. The third group, “Tb emuls 
a,” received the same thick emulsion, undiluted, as that used in 
making “Tbag b.” The total number of bacilli received by 
animals of the third group was evidently much larger than that 
given in the agar doses. Avian 6090, for example, received 
twenty-two times as many bacilli as avian 6074. The fourth 
group, “Tb emuls b,” received thick emulsion in salt solution of 
a 55-day glycerin agar culture of the avirulent strain. 
All doses were inoculated subcutaneously in the right inguinal 
region. The volume of the dose in all groups is given in the 
tables. 
All agar-inoculated animals of series 2 showed marked in- 
filtration around the agar mass, and seventeen days after in- 
oculation a lump of agar-plus tissue, the size of a hazelnut or 
larger, was present. As shown in Table II, few had any marked 
lesions ninety days after the avirulent inoculation. At the time 
of the inoculation of virulent bacilli all were apparently healthy 
and all had gained in weight. 
The virulent dose was exactly the same as that given in series 
1 and was given in the same way and at the same time. Avian 
6079 was sacrificed, avian 6096 died of some intercurrent in- 
fection before receiving the virulent dose, and Nos. 6076, 5888, 
and 6098 died of accidental plague infection of rat-flea origin 
after receiving the virulent dose. All others survived the vi- 
rulent dose for at least one hundred sixty days and at autopsy 
showed typical lesions of tuberculosis. 
Series 3, Table IJ].—In series 3 the animals received two avi- 
rulent doses. The second was given fifty days after the first. 
In preparing the first dose, an emulsion of a 26-day culture and 
one of an 11-day culture of the avirulent human strain were 
mixed and added to a 5 per cent glycerin agar containing 2 
per cent agar, in the proportion of 1 cubic centimeter of emulsion 
to 85 cubic centimeters of agar. One animal received a thin 
emulsion without agar. 
