1165 
According to these tests, the species-specificity of haemoglobin is 
certainly not much less marked than that of the serum-protein. 
Somewhat striking is the fairly strong reaction with mouse-blood, 
yet similar reactions are also known to occur in the case of pre- 
cipitin reactions with serum albumin. It would be interesting to 
prove, whether the group reaction mentioned also takes place with 
Other precipitin sera against horse-haemoglobin. After the tests had 
stood about 20 hours some further weak group-reactions were 
observed. 
A reaction for haemoglobin solutions generally succeeds with the 
help of the inhibition test *). If to the tests, containing the quantities 
of horse-haemoglobin and the corresponding immune-serum mentioned 
above, 0.05 cc. of a 1°/, solution of haemoglobin belonging to 
different animal species was added, an inhibition of the precipitation 
took place, which as experiments with the addition of smaller 
quantities of haemoglobin showed, was with one pul strongest 
in the case of horse and ass haemoglobin. 
Haemoglobin solutions. 
| | 
horse ass | dog | Ox sheep | rabbit aen | |_control 
| my 
0 | 0 | “0 | 0 | 0 | 0 | On te | tale 
I also endeavoured to investigate by means of the inhibition 
reaction the question of the presence of a common species-specific 
group in serum-protein and haemoglobin. From this it appeared 
that by the addition of 0.05 ee. of normal serum belonging to 
different animal species, to the mixtures of haemoglobin and their 
antibodies, the precipitation was inhibited. 
When serum from 11 different species of animals were tested 
simultaneously the inhibition was strongest and equally marked in 
the case of the serum from the horse, ass and two other kinds of 
serum. The result, therefore, does not yet permit of any definite 
conclusions. It is, however, possible, that through further variation 
(immune bodies against other kinds of haemoglobin) and perhaps 
through modifications of the method of experiment, a positive result 
will be obtained. 
1) LANDSTEINER. Bioch. Z. 98, 115, 104, 280, HALBAN u. LANDSTEINER. Munch. 
med. Woch. 1902. NO. 12. 
