Taking Table 4 as it stands, the order of potency of the eight normal serums
is as follows :—
Dogserum
...
...
...
...
...
...
...
...
...
1
Man„
...
...
...
...
...
...
...
...
... 2
Goat„
...
...
...
...
...
...
.:.
...
3
Sheep,,
...
...
...
...
...
...
...
...
...
4
Rabbit„
...
...
...
...
...
...
...
...
...
5
Hen„
...
...
...
...
...
...
...
...
... 6
Guinea-pig serum...
...
...
. . .
—
—
. . .
. . .
7
Horse...
8
, ,
...
...
...
".
...
...
...
If, however, one makes allowance for the close relationship of the goat and sheep
and omits from the calculation the action of these two serums on each other's
RBCs, which is nil, the order becomes—
Dogserum
...
...
...
...
...
...
...
...
...
1
Goat
...
...
...
...
...
...
...
...
2
Man„
...
...
...
...
...
...
...
...
...
3
Sheep,,
...
...
...
...
...
...
...
... 4
Rabbit„
...
...
...
...
...
...
...
...
5
Hen„
...
...
...
...
...
...
...
... 6
Guinea-pig serum ...
...
...
...
...
...
...
...
...
7
Horse
...
...
...
...
...
...
...
...
...
8
which would probably be the more correct if a larger number of species could have
been taken into account.
Further, if the relative resistances of the RBCs of the eight species to lysis
by normal serums is calculated approximately from the figures available, we get—
Dog RBCs, the most resistant ...
...
...
...
...
...
...
I
Goat„
...
...
...
...
...
...
...
.
Sheep
„...
...
...
...
...
... ... ... 3
Horse„
...
...
...
...
...
...
...
4
Man„
...
....
...
...
...
...
...
...
5
Hen„
...
...
...
...
...
...
... 6
Rabbit„
...
...
...
...
...
...
7
Guinea-pig RBCs, the least resistant
...
...
...
...
...
...
8
If the order is again modified by allowance for the negative action of goat and
sheep serums on each other's RBCs, it becomes
Dog RBCs, the most resistant ...
...
...
...
...
...
...
r
Goat„
...
...
...
...
...
...
2
Horse„
...
".
...
...
.'.
3
Man„
...
...
...
...
...
...
...
4
Sheep„
...
...
...
...
...
, ...
...
...
...
5
Hen„
...
...
...
...
...
...
...
...
...
6
Rabbit„
...
...
...
...
...
...
...
...
7
Guinea-pig RBCs, the least resistant
...
...
....
...
... 8
So it seems that dog serum, which we showed on P. 27 to contain the most
amboceptor, has the most resistant RBCs, and g uinea-Pig serum, which we showed
on pp. 24 and 27 to contain the most complement, has the least resistant RBCs. The
results obtained are not sufficiently definite to permit more than this to be said.
*
*
*
*
*
i
(9) It is by no means easy to sensitize RBCs in a heated, normal foreign
serum, even when that serum in its unheated state is strongly lytic towards them.
For instance, 7 parts of fresh sheep serum lysed 1 part washed rabbit RBCs.
Washed rabbit RBCs were sensitized in this sheep serum in several proportions
from 2 . 6—1 to 85 . 2—1, washed and complemented with fresh guinea-pig serum.
No more lysis was shown in the more highly sensitized series than in the lower
ones, and it made no difference to present the sensitizer to the RBCs in four
successive portions instead of altogether.
It is evident that by this method the presence or absence of an amboceptor
for any particular RBCs in a heated serum cannot be ascertained with certainty,
assuming as we have done that guinea-pig serum is an efficient complement on all
occasions. It appears to be so for artificial amboceptors, so there seems to be no