230                     Corynebacterium equi in a She-Buffalo

added and incubated for two hours at 37°C. Then the requisite quantities
of haemolysin and sheep R. B. C. were added. The contents were mixed
well and incubated for one hour at 37°C.

A healthy rabbit serum was also tested against both the antigens for
control.

In addition, a complete set of the usual controls for the reliability of the
components were kept as follows:—Serum control with one-tenth dilution
of serum, complement, haemolysin and R. B. C, but with no antigen ; antigen
control with ½ c.c. of antigen, complement, haemolysin and R. B. C, but
with no serum; haemolytic system control with two units of haemolysin
complement and R. B. C, but with neither serum nor antigen; R. B. C.
control with two per cent sheep R. B. C. in normal saline only.

All controls were satisfactory.

The result is tabulated below (Table II).

                                                                 TABLE II

NOTE :—C. 13 = C. equi of foal pneumonia origin.
C. 200 = Diphtheroid of she-buffalo origin.

(—)      = Complete haemolysis. . . . No fixation of complement.

(+)      = 25 per cent inhibition of haemolysis .

(+ +)    = 50 per cent inhibition of haemolysis .

(+ + +) = 75 per cent inhibition of haemolysis .

(+ + + +) = 100 per cent inhibition of haemo-
lysis.....

Degrees of fixation of comple-
ment.