21. Heterothallic fertilization occurs once two haploid mycelia ( homokaryons ) of different mating types have made contact. 22. When environmental conditions are suitable, the chlamydospores germinate, producing mycelia ( or hyphae ) and sporangia. 23. Towards the end of the cereal host's growing season, the mycelia produce structures called telia. 24. Thin hyphae make up the mycelia , measuring from 1 to 2 micrometers ( ?m ) in diameter. 25. It produces branching substrate mycelia and spherical spore vesicles on aerial hyphae that contain non-motile spores. 26. The base of the fruit bodies are attached to the substrate by rhizomorphs ( thickened cords of mycelia ). 27. It also produces a chitinase A able to produce protoplasts from " Schizophyllum commune " cultured mycelia . 28. The optimum temperature for the growth of mycelia is, while the optimum for the growth of primordia is. 29. The spores then germinate and the mycelia , or vegetative structure of the fungus, grows into the wood. 30. It has been suggested the electrical stimulus of a lightning bolt striking mycelia in logs accelerates the production of mushrooms.
