STUDY OF DELAYE!) 01! « LATENT » TUBERCULOUS INFECTION 605 
be advantageous to dividethe second stage intotwo sub-stag^s 
indicated by the letters À and B in the above table in which 
reference is made only to lésions visible to the naked eye 
after the organs hâve been exposed by dissection. It is 
however easy to prove, as the writer has done, that the lym- 
phatic ganglia and other organs are affected several daysbefore 
lésions are visible to the eye. To do this it is sufficient to test 
these organs by inoculating cobayes with them at various infer- 
vals after the original animal had been inoculated. 
The results of some of these tests when a small number of 
bacilli is used may be summed up as follows : 
The popliteal gland on the side inoculated is usually infec¬ 
tive 48 hours after inoculation; 
The superficial inguinal glands are usually infective from 72 
to 96 hours after inoculation; 
The spleen is usually infective from 96 to 120 hours after 
inoculation. 
The extent of the lésions is inlluenced both by the duration 
of life after inoculation and by the number of bacilli in the 
material tesled. To ascertain the influence of the number 
of bacilli, four cobayes were inoculated with the sédiment of 
equal quantifies of various dilutions of a sample of milk obtai- 
ned from a cow with advanced tuberculosis of the udder. At 
the end ol 15 days these four cobayes were killed and tubercu- 
lous lésions were found in each. There was a distinct relation 
between the amount of the tuberculous milk (and, therefore, 
of tubercle bacilli) and the extent of the lésions as is shown 
by the following table. 
DILUTION 
QUANT1TY OF ORIGINAL MILK 
contained in the 
MATERIAL INOCULATED 
APPROXIMATE 
NUMBER 
of 
TUBERCLE BACILLI 
DEGREE OF TUBERCULOSIS 
observed 
AT THE END OF 15 DAYS (*) 
1 /:100.000 
1/10.000 
1/1.000 
1/100 
0 C.C. 0002 
0 C.C. 002 
0 C.C. 02 
0 c. c. 2 
At least 30 
At least 300 
At least 3.000 
At least 30.000 
2nd A. Lésions small. 
2nd A. to B. dilto. 
2nd B. 
3rd Lésions larger. 
(*) As indicated by lésions visible to the naked eye. 
