English: Spores with mesh-like ornamentation:

Tuber aestivum (summer truffle) is a fungus that, in line with the taxonomic classification, belongs to the division Ascomycota, family Tuberaceae. The species forms globular, fully-enclosed fruiting bodies, so called "sporocarps". On the surface, the fruiting bodies are covered with black sheath (peridium) - which comprises big verrucas - while inside, the spore-bearing mass (gleba) occurs. The gleba is compact, marbled with thin white and dark brown venules. During the fruit body early development, the gleba is completely white, but with maturation, spores and dark brown venules are formed. A microscopic slide of the gleba is prepared in order to observe the spores. The sporocarp that has been cut into half is positioned on a binocular, with the gleba being in the focus. A minute, thin piece of the gleba is cut with a razor thereby bearing in mind that a portion of the brown venules where spores are expected to have developed ought to be included in the extracted material. By using tweezers, the material is laid onto the slide in Melzer's reagent, and a cover glass is placed on top. By gently pressing with absorbent paper, the material is smeared between the glasses, the air is expelled, and the excess reagent is collected.

The microscopic slide is first observed at 100x magnification (10x objective lens), where asci filled with four or five, less frequently with three or six, ellipsoid spores are noticeable. Subsequently, at 400x magnification (40x objective lens), two asci, one with four and one with three spores, and later one ascus with five spores, are observed. It is evident that the spores located in asci with a lower number of spores are larger (e.g. three-spored ascus) while in asci with a higher number of spores, they are smaller in size (e.g. five-spored ascus). At 1,000x magnification (100x objective lens), all the details in the structure of the spores are visible; first the focus is laid on the shape of the spores, which are ellipsoid, and also on ornamentation rising above the spore wall and resembling thorns; later, the focus is on ornamentation forming mesh-like openings, and creating irregular polygons with sharp angles.

Planned and performed by Slavica Tofilovska and Katerina Rusevska, Department of Biology, FNSM, Ss. Cyril and Methodius University, Skopje, Macedonia.