CHAPTER XXII 



BRYOPHYTES 



MUSCI 



In general, the mosses are more conspicuous than the liverworts and 

 easier to collect. Many of the most desirable forms fruit only in the 

 spring, but something can be found throughout the summer and 

 autumn and some, like species of Sphagnum, pass the winter with the 

 antheridia and archegonia in advanced stages of development. 



For herbarium specimens, mosses should be pressed very lightly, 

 changing the blotters 3 or 4 times the first day, otherwise the plants 

 will have a dull brown color. Some prefer to keep the mosses in boxes, 

 without any pressing. 



Material is more troublesome to fix than in the liverworts because 

 small bubbles of air hinder the penetration of the fixing fluid. Use the 

 air pump or aspirator. Older archegonia and capsules which have 

 turned brownish add to the difficulties of the technique. 



The Chicago chromo-acetic-osmic acid formula, or this formula 

 without the osmic acid, fixes well. If neither an air pump nor an 

 aspirator is available at the time of fixing, Land's formalin alcohol so- 

 lution (6 c.c. commercial formalin to 100 c.c. of 70 per cent alcohol) 

 will be more satisfactory. Dr. Land probably would now add about 

 3 c.c. acetic acid to the mixture. 



Protonema. — Protonema of some moss can be found at any season. 

 Look between the sidewalk and the curb, in shady places close to 

 buildings, in the field and in the woods. Greenish patches resembhng 

 Vauchcria may be moss protonema with buds of the young leafy 

 plants. Where there are recognizable leafy plants, there may be some 

 good protonema, but young buds are likely to be scarce. The brownish 

 bulbils, which are quite common in mosses, can be seen with a pocket 

 lens. Some of the very small leaved mosses found on pots in the fern- 

 ery or on benches in greenhouses, often show this mode of reproduc- 

 tion. Protonema is easily grown from spores. 



Fresh green moss protonema will stand, without damage, what 

 might seem to be very rough treatment. Scrape a thin layer off from 

 the soil, put it in the palm of your hand, let water drip on it, and pat it 



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