1910. | Complement Deviation in Mouse Carcinoma. 363 
quantities dealt with, it is not possible to recognise a slight degree of laking, 
and, in particular, it is not possible to determine quantitatively the degree to 
which the red cells are laked, as is possible when large amounts of cells and 
fluid are available. 
When tumour extract was added at 37° C. to human serum in the 
amounts given in Table II, and after the lapse of an hour and a-half the 
mixtures were transferred to tubes containing sensibilised red blood cells, 
laking took place slightly, but distinctly less readily, the first tube remaining 
free from laking, and the second tube presenting, instead of complete laking 
at the end of 90 minutes, only a slight degree of Jaking, which was slow in 
appearing. In the remaining tubes rapid and complete laking occurred. It 
follows, therefore, that the antigen is of itself capable of fixing a certain 
amount of the complement contained in the human serum employed. 
Table I1.—Complement Fixation by Mouse Tumour Extract. The contents 
of each tube, after standing at 37° C. for 14 hours, were added to 
sensibilised red cells obtained from 0:02 c.c. of a 24-per-cent. suspension 
of the red cells of the rabbit, and the mixture kept, with occasional 
shaking, at 37° C. for a further period of 14 hours. 
| vn 0:85 per Degree of hemolysis at the end of— 
No. ek cent. AMCIC Cig lamas aR ; 
of in team solution | (tumour 
tube ee of sodium | extract) Ba ; : | Ye itgubs 
"| serum. Giiende ; 30 mins. 60 mins. 90 mins. (at room | 
temperature). 
C.c. C:C: G.c. 
1 0 ‘001 0°03 0°03 Not Not Not Not 
recognisable | recognisable | recognisable | recognisable | 
2 0 -003 0-03 0-03 5 Shght Slight Slight 
3 0 ‘009 0 ‘038 0°03 Slight Nearly Complete Complete 
. complete | 
4, 0 :027 0:03 0°08 Partial Complete ‘ 5 
5 0-081 0°03 0-03 Nearly - - é 
complete 
| 
When, in addition to tumour extract, 0°03 c.c. of inactivated serum 
obtained from a normal mouse was added to the quantities of human serum 
given in Table III, and, after being kept at 37° C. for an hour and a-half, the 
mixtures were transferred to tubes containing sensibilised red blood ‘cells, it 
was found that the action of the complement was further reduced, no 
hemolysis occurring in the second tube, and the amount in the third tube 
being considerably diminished. 
If, instead of employing normal mouse serum, the serum of a mouse with a 
large tumour was employed, the course of a positive reaction was such as is 
