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.
Most ferns reproduce by alternating generations between successive asexual and sexual forms. The sexual form, called the gametophyte or prothallium, is a tiny kidney-shaped haploid (N) plant that is difficult to find in the wild. The asexual form, or sporophyte form, is represented by the fern plant as it is commonly known and is diploid (2N). Sporophytes can reproduce either by vegetative cloning via their rhizomes or through spore formation via meiosis. Spores, rather than gametes, are the unicellular, haploid products of meiosis in fern plants. Spores in turn undergo mitotic cell divisions to produce the multicellular, haploid gametophyte. Relative to the familiar sporophytes, the fern gametophytes are small and inconspicuous. Commonly in primitive vascular plants, the haploid gametophyte phase occurs in a manner that allows it to be surrounded by tissues of the parent sporophyte, such as within cones, seeds, or pollen grains.