Abstract
Polyhedral virus-like particles, approx. 39 nm in diam. (39-nm VLPs), have been studied by electron microscopy in thin sections of Lentinus edodes (Berk.) Sing. monokaryon. They were common in the cytoplasm and in vacuoles of the hyphal cells, either irregularly scattered or in aggregates which were sometimes crystalline especially in old mycelium. Crystals were found almost exclusively within cytoplasm and vacuoles in disintegrating cells. Examination of fused monokaryons suggests that the cytoplasmic 39 nm VLPs may move from one cell to another through the breakdown of a dolipore septum during dikaryotization.