On the Appearance of Certain Amœboid Bodies in the Blood of Vaccinated Monkeys (rhoesus) and Children, and in the Blood from Cases of Variola

1. The claim of L. Pfeiffer that small granular amoeboid bodies are present in the blood of vaccinated children and calves, and in the blood from cases of variola, during the stage of fever is confirmed. A nucleus has not been positively made out in any of these bodies. 2. Granular amoeboid bodies, having a diameter about one-third that of a red blood cell, appear, also, in the blood of the monkey during the active stage of vaccinia and disappear with the decline of the local inflammation. 3. A body of like appearance, granulation and size may occasionally be found in the normal blood of monkeys and children. 4. Pale amoeboid bodies, containing a few dark pigment-like granules, are present in the blood from cases of variola and in the blood of the variolated monkey. Bodies of like appearance may occasionally be found in the blood of vaccinated children and monkeys.