collegium musicum. a group of usually amateur musicians, often connected with a university, who meet to study and perform chiefly old or little-known music.
Spores and Sporangium. Ferns differ from flowering plants and trees because they do not produce seeds. Instead, ferns reproduce using spores. The sporangium is the structure responsible for producing and releasing spores. Sporangium form in many different ways, sometimes appearing as brown fruitdots on the undersides of leaves. Others grow as slender stalks up from the plant. When the sporangia burst, the wind carries spores to new ground, where they form reproductive structures that, if fertilized, will grow into a new fern.
The asexual form, or sporophyte, is represented by the commonly known and cultivated fern plant, and is diploid (2N). Sporophytes can reproduce either by vegetative cloning via their rhizomes or through spore formation. The prothallia are equipped with multiple antheridia (male reproductive organs) and archegonia (female reproductive organs). As heterosporous plants, the fern's antheridium produces free-swimming sperm and its archegonium produces eggs. The products of their unions are zygotes, and fertilization occurs when the sperm swim through an opening (operculum) from each antheridium along a thin film of water to the neck of each archegonium.