The various vital reactions and pathohistological changes were observed on the administration of anti-gallbladder and colon mucosa-rabbit's serum which was obtained from the sensitization of rabbit by the emulsion of canine gallbladder and colon mucosa. And the results were as follows. 1. The intensity of vital reaction occured to the sensitized animal on the administration of anti-canine gallbladder and colon mucosa-rabbit's serum was depended upon the difference of each individual case, but it became intense in proportion to the antibody titer of antiserum administrated, dosis of injection and number of injection. 2. As for the serological change on the administration of the above described organic antiserum, the antibody titer to each antigen became the highest around 1 week after the administration and it returned to the preadministrative titer around 2 weeks after the administration. At that time, the vicissitude of complement titer did not show remarkable change respectively. 3. As for the change of serum protein picture, a little increase of γ-globulin was seen in the group with the administration of anti-canine gallbladder mucosa-rabbit's serum, but it was not remarkable in the group with the administration of anti-canine colon mucosa-rabbit's serum. 4. Since the pathohistological changes of each organ caused by the administration of anti-canine gallbladder and colon mucosa-rabbit's serum, those organic antiserum showed having the organic peculiarity comparatively.