Following the technique of our department the author performed the bonemarrow tissue culture of ths human sternum and the rabbit femur in relation to age and observed the cell proliferation (growth area and the cell density), and the cell functions (the wandering velocity of neutrophils and psendoeosinophils, the carbon-particle phagocytosis and vital staining of the same), and obtained the following results.
1. Summarizing the cell proliferation in the bone-marrow tissue culture, in human the proliferation is high in the descending ordar of age 15, in the twenties, thirties, fifties, while in rabbits, it is high one, two and six months after birth followed by 5 days after birth; and below that is in the orber of one, two and three years old.
2. The wanderinh velocity coincides well with the rate of cell proliferation of both neutrophils and pseudoeosinophils, and in human it is great in the order of age 15, in the twenties, thirties, fifties, and seventies, while in rabbits it is greatest one and two months after birth, followed by 6 months, 5 days, one, two, and three years after birth. 3. The carboneparticle phagccytosis parallels with the cell proliferation and the wande ring velocity, and in human it decreases along with the advance in age, while in rabbits it is most active one, two and 6 months after birth, followed by 5 days, one, two and three years after birth. 4. As for the vital stainings the discoloration of stained granules is delayed in young age both in human and rabbits, and also the average stainability at the early stage of the culture shows a low value. Namely, in human at the age 15 the delay in the dircoloration is longest, and the discoloration occurs earlier along with the abvance in age as in the twenties, thirties, fifties, and seventies in ascending order. 5. From these results the functions of bone marrow in human is most active at the age of 15 years and it decreases along with the abvance in age, while in rabbits it is most active one to six months after birth, followed by 5 days after birth, and thereafter at one, two and three years the functions gradually decrcases.