Abstract
Author intended the sero-immunologic studies of human meconium as the series of studies concerning fetal serum, placenta and so on, and then obtained the results as follows;
1) When rabbits are injected repeatedly with the extract of human meconium, the antiserum can be obtained high titer precipitin reaction on human serum.
2) Researching production of precipitin about rabbit's serum immunized with human meconium of the 7, 8, 9 and 10th pregnant months separatedly, author cannot find striking differences on antigenity in each months.
3) Rabbit's serum immunized with human meconium has very strong species specifity.
4) In human meconium exist specific protein fractions which are not contained in the adult human serum and these fractions are considered to coincide with those exist in the fetal serum and there were very small quantities.
