s.0B, 2 Barber: Experiments on Immunization 151 
Three animals (Nos. 5990, 5991, and 5992) received this dose 
intraperitoneally; animal 5989, both intraperitoneally and sub- 
cutaneously ; and the rest, subcutaneously in the inguinal region. 
The local reactions following the first subcutaneous dose were 
much the same as in the other series—infiltration for a few days 
and a hard lump which persisted for ten days or more. None 
showed more than a scar forty-four days after inoculation. One 
animal, No. 5986, died of sepsis two days after inoculation. 
The character of the second inoculation is the same as in series 
2 and is shown in Table III, where the same symbols are used 
in describing the dose as in Table II. All received the agar 
mixture, all a dose of 3 cubic centimeters, and all were inoculated 
subcutaneously in the right inguinal region. 
The reaction following the second avirulent dose was more 
marked than in animals of series 2 not previously treated, which 
received the same dose. The effects were more permanent also, 
as may be seen by comparing the results in the two series after 
ninety days (Table III). This more marked reaction was prob- 
ably due to a sensitization resulting from the first dose. All 
were well and gaining in weight when the virulent dose was 
given. 
The virulent dose of series 3 was of the same character and 
amount as in the other series and was inoculated on the same 
day, in this series one hundred, twenty-seven days after the 
second avirulent dose and one hundred seventy-seven days after 
the first. Animal 5991 died of some intercurrent disease before 
receiving the second avirulent dose. 
Twelve controls received the virulent dose at the same time 
as the animals in series 1, 2, and 3. The same dose of sputum 
bacilli was given to all. The immediate reaction following the 
test dose was small, and on the whole, slightly less than that of 
the treated animals. The control group is given in Table IV. 
In Tables I to IV the entry “Tb” indicates that the animal 
showed lesions of tuberculosis at autopsy. These in general were 
most marked in the inguinal glands, spleen, liver, and lungs. 
Tubercles in the mesentery or kidneys were rarely shown in the 
gross examination. Lung lesions were almost constant, con-: 
sisting usually of many consolidated areas, although no cavity 
formation occurred such as has been described by some authors 
for chronic tuberculosis in guinea pigs. 
SUMMARY OF THE RESULTS GIVEN IN TABLES I, II, II, AND IV 
With regard to a possible immunization of the animals as 
judged by the length of time of survival after receiving the 
