CULTURE OF LIVERWORTS AND MOSSES 215 



THE CULTURE OF LIVERWORTS AND MOSSES 



205. The culture of liverworts. Aciuatic liverworts, such as liicciocarpus 

 natans and some species of Riccia, will sometimes grow fairly well in large 

 glass aquaria, but they must have pure air and considerable water. They will 

 do much better in tanks or cement basins in greenhouses. The terrestrial 

 liverworts, such as MarcAan^/a, Lunid<irl(i, Comctphalm, and related types, 

 grow readily on damp soil in greenhouses or in large vessels covered with 

 glass. These forms and various mosses are frequently present in ill-kept 

 greenhouses. They will not do well in very bright light, preferring shaded 

 situations, and must have abundant moisture in the earth. If convenient, 

 it is well to cultivate them on soil from their habitats. 



206. The culture of protonemata. Moss spores germinate readily, and il is 

 not difficult to obtain luxuriant cultures of protonemata. These frequently 

 appear over the surface of earth in flowerpots in greenhouses, and then 

 somewhat resemble the more common growths of Vaiirheria. Cultures of 

 the spores are conveniently made in bulb pots or other wide pots set in sau- 

 cers of water. After filling the pot with earth to an inch from the top, it is 

 well to heat it for two or three hours in a steam sterilizer to kiU fungi which 

 might be troublesome, but this is not absolutely necessary. 



The spores of many of the common mosses of the fields will grow readily, 

 but species of Funaria are especially satisfactory. The spore cases may be 

 crushed over a sheet of paper to remove the spores, which are thengently 

 blown over the surface of the earth. The top of the pot is covered with a 

 piece of glass and the culture is watered from the saucer below. The earth 

 should be merely moist, not wet, for too much moisture may result in the 

 death of the culture by "damping off" from the growth of fungi. The 

 earth will shortly become covered with a growth of green filaments. After 

 two or three weeks, buds will be developed, followed by the appearance of 

 the leafy moss plants. ■ 



207. Moss cultures. A thick growth of leafy moss plants generally arises 

 from the protonemata as described above. These plants will in time develop 

 sexual organs, the antheridial plants being easily distinguished by the rosette 

 of expanded leaves around the yellow or orange-colored clusters of anther- 

 idia. The archegonia will not be fertilized if the culture is watered entirely 

 from the saucer below. When sporophytes are desired the culture must be 

 flooded with water, first closing with a cork the opening in the pot below. 

 It should remain flooded for an hour or more, aftep which the water may 

 be allowed to run off. All ripe archegonia and antheridia will have opened, 

 and the eggs, having been fertilized, will develop sporophytes. By succes- 

 sively flooding the culture at intervals, sporophytes in varioua stages of 

 development may be obtained. 



