With administration of 20 mg./k. of SM (streptomycin) per day to 8 cavities induced experimentally in the lungs of adult rabbits, and 10 mg./k. of INAH (isonicotinic acid hydrazide) to 5 cavities similarly induced, continuously for 30 days, the author has obtained Spalteholz's preparates after injection of pigment into the lungs and patho-histological specimens as well and after studying these specimens, he has arrived at the following conclusions: 1) The vascularization of the cavity walls receiving either SM treatment or INAH therapy, has been similar to that of the control group as previously mentioned in Part One. 2) In the SM treatment, the new formation of blood vessels and hyperemia in granulation tissues of the cavity-wall show no especial difference as compared with those of the control group. 3) In the INAH treatment, marked hyperemia of capillaries and new formation of blood vessels, and in places, hemorrhage in granulation tissues of the cavity-wall have been observed.