Again Piptoporus betulinus. Technovit 7100 2 um cuts stained by Calcofluor white, excited at 450 nm and observed above 515 nm. Zeiss Universal Photomic II with 63x/1.25 (oil) Neofluar . Camera Renusco DTM500 with ScopePhoto imaging software.
These pictures may not be technically beautiful, but I like what they tell me.
The basidiospores of Piptoporus betulinus look round to ellipsoid having a size of 1.8- 2.0 um (https://www.mikroskopie-forum.de/pictures004/141840_55139744.jpg). In the second picture the 4 spores stick together (https://www.mikroskopie-forum.de/pictures004/141840_26904625.jpg).
The picture of the clamp connection (https://www.mikroskopie-forum.de/pictures004/141840_55947063.jpg) of one of the generative hyphae tells us that the mycelium is heterokaryotic, but we knew that already because there are basidiospores present.