The bryophytes, which include liverworts, hornworts and mosses, reproduce both sexually and vegetatively. In the bryophytes, including liverworts, hornworts and mosses, sex chromosomes are common. All bryophytes, i.e. liverworts, mosses and hornworts, have the gametophyte generation as the most conspicuous. In the bryophytes (liverworts, mosses and hornworts), the sexual gametophyte is the dominant generation. This centre has also appreciable cryptogamic collections that include fungi, lichens, algae, bryophytes and pteridophytes. They also include the "bryophytes", of which mosses and liverworts are the most common. In many plants such as bryophytes, ferns, and gymnosperms, egg cells are formed in archegonia. In plants such as bryophytes, ferns, and a few others, spores germinate into independent gametophytes. Plants that produce spores instead of seeds, like bryophytes and ferns, also produce embryos. Antheridia are present in the gametophyte phase of cryptogams like bryophytes and ferns. He divided Cryptogamia into four orders&colon; Algae, Musci (bryophytes), Filices (ferns), and Fungi. Some bryophytes, most lycophytes, and some ferns are heterosporous (two kinds of spores are produced). The sporophyte of Riccia is the simplest amongst bryophytes. Distinct adaptations observed in bryophytes have allowed plants to colonize Earth's terrestrial environments. Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae.