430 MUSCI. 



Phylum 3. BRYOPHYTA. 



]\IOSSES AND HePATICS. 



Small plants, producing minute usually spherical bodies (spores) 

 in capsules, from which arise a protonema on which are borne 

 the plants (gametophytes) bearing archegonia and antheridia, from 

 which the fruit (sporophyte) is formed, which in turn bears spores- 

 There are two classes which differ from each other as follows: 



stems erect or prostrate, having leaves more or less equally developed on all sides ; 



calyptra at the apex of the capsule. Class 1. Musci. 



Stems usually prostrate, with the leaves, when present, 



unequally developed on the upper and lower surfaces ; 



calyptra at the base of the capsule. Class 2, Hepaticae. 



Class 1. MUSCI. 



Mosses. 

 Contributed by Elizabeth G. Britton. 



Terrestrial, epiphytic, or rarely aquatic plants, showing two dis- 

 tinctly marked but closely connected and continuous phases of 

 growth, or alternate generations. Plant (gametophyte) usually 

 differentiated into stem, leaves and rhizoids (true roots none), 

 arising from a more or less ephemeral protonema, which originates 

 from the spore, forming either a filamentous or thallose growth. 

 Sexual organs borne either apically or laterally on the stem, usually 

 in special buds ; antheridia and archegonia on the same plant or on 

 separate plants. Antheridium containing ciliate sperms. Arche- 

 gonium a single egg, after the fertilization of which the embryo 

 develops into the fruit (sporophyte), rupturing the walls of the 

 archegonium in its growth. Fruit (sporophyte) usually forming 

 a pedicel, the base of which is imbedded in the vaginule ; upper part 

 of the archegonium, carried up by the elongation of the pedicel, 

 forming the calyptra, which in most mosses covers and protects the 

 sporogonium Avhile it is developing. Capsule (sporogonium) usually 

 with a central axis (endothecium) forming the columella, around 

 which the spore-sac (archesporium) is developed, usually separated 

 from the walls (amphithecium) by air-spaces and chlorophyl-bear- 

 ing tissue. Capsule dehiscent regularly by a lid or slits, or inde- 

 hiscent (cleistocarpous) ; when dehiscent frequently developing 

 specialized appendages around the mouth, constituting the peri- 

 stome, which serves in the dissemination of the spores. All the 

 species of Bermuda are native. Their spores were presumably 

 brought on the wind. There are two orders represented in the 

 Bermuda Flora. 



Capsule borne on a pseudopodium ; spore-sac arching over the columella. 



I. Sphagxales. 



Capsule borne on a more or less elongated pedicel ; spore-sac 

 cylindric, surrounding the columella and perforated by it at the 

 base and apex. II. Brtales. 



