Abstract
Ultrastructural studies were carried out on one case each of reticulum cell sarcomaand lymphosarcoma in sw-ine.Two phases, proliferous and functional, were observed in reticulum cell sarcoma.The cell of the proliferous phase contained a rather small number of organelles, and thatof the functional phase possessed numerous organelles.In the case of lymphosarcoma, there were germinoblast-like and lymphocyte-like cellsin the neoplastic tissues. An increase in number of ribosomes and polyribosomes in thecytoplasm and the formation of a nuclear pocket were characteristic of both types of cells.
