The A. A. intending to use Bartonellosis of splenectomized rats as a test of spleen functions, since there is evidence of an hormonal protective mechanism, study the evolution of anemia in this animal after spelenectomy. They discuss the principal aspects and papers about the subject. They compare the influence of inespecific trauma as regard the appearance of this infection. They profit the material for the verification of the terapeutics effect of barium penicillin produced at the Instituto Oswaldo Cruz, over the experimental Bartonella muris anemia of splenectomized albino rats. They describe the methods and give the results in respect of the extreme sensibility of the animals employed and the ineffectiveness of penicillin at least in the dosage used.