204 Dr. Russell. The Manifestation of Active [Mar. 15, 



Exp. T/40 C. Mice 1—11 inoculated in right axilla with 0-02 c.c. (20.10.11). 

 Tumours excised (22.11.11), and the animals inoculated in left;"axilla 

 with 0-02 c.c. of 63/55 E (24.11.11). 



Fig. 3. — The growth of tumour strain T followed by surgical removal does not render 

 mice unsuitable for subsequent inoculation. 



these strains are ill-suited for the investigation of resistance. Tumour 

 strain 206 is, however, an exception, as it grows in a very high percentage 

 of inoculated animals, and the date of onset of spontaneous absorption is 

 remarkably regular. Several experiments have been made with this 

 carcinomatous strain, but the results obtained have been so decisive that 

 only one need be illustrated. The result of this experiment is given in 

 fig. 4, where it will be seen that 11 days of growth of this strain in 11 

 mice has been sufficient to render every one of these animals unsuitable for 

 the growth of carcinoma 63. 



Between these two extremes, the other transplantable mouse tumours, 

 carciuomata and sarcomata, range themselves according as they render 

 animals in a higher or lower percentage unsuitable for re-inoculation. 

 Several of these strains have been tested, and resistance to re-inoculation 

 has been found in a percentage varying between 30 and 75. One of these 

 carcinomata, strain 199, exhibits certain peculiarities in its manner of 

 growth, which were described in a communication published in these 



