Abstract
Bacterial virus strain A active against Pseudomonas solanacearum E. F. Smith strain B19 was purified by the differential centrifugation at 26, 000g for 60 min., 59, 000g 60 min., and 20, 000g 120 min. According to the electron-microscopic observations, the purified virus appeared uniformly as the spherical particles approximately 70-80mμ in diameter (Fig. 1). The surface of virus particle was not smooth, and assumed to have some internal structures within the particle.
The cell contents of host bacteria, infected with the virus, were filled with very small protoplasmic particles and the new virus particles. After the latent period, the membranes of the infected bacterial cells were strongly ruptured and the proliferated new virus particles were liberated from the bursting cells (Fig. 3).
