BBTOPHTTA. 193 



and 107); Fontinalis, large floating mosses, common in 

 brooks and rivulets; Cylindrothecium; Climacium (C, 

 americanum is a large tree-shaped moss); Hypnum, the 

 bog-mosses, etc. 



PraeUcal Studies. — (a) Collect several kinds of mosf es in fruit : some 

 of these should be of large species. Note the brownish root-liairs, 

 the stem and leaves, the spore-fruit composed of a slender stalk bear- 

 ing a spore-case, the latter in some species covered by a membranous 

 or hairy cap (calyptra). 



(J) Select a broad-leaved species. Mount a single leaf in water, 

 ^nd examine with a low power. Note that the leaf is (generally) a 

 single layer of cells, and that the midrib (if present) is composed of 

 elongated cells. Make cross and longitudinal sections of stems of 

 the larger species, and note that some of the cells are elongated and 

 flbre-like. 



(c) Place a spore-case under the microscope and examine with a 

 low power, noting the lid (Fig. 106, O). Now remove the lid and 

 observe the teeth (Fig. 106, H). The teeth may be studied still bettei 

 by splitting the spore-case from base to apex and then mounting in 

 alcohol, and afterwards adding potassic hydrate. In this specimen 

 spores may be studied also. 



(d) Split a young spore-case and examine the external surface of 

 the lower part for breathing-pores. 



(e) Collect a number of mosses not in fruit, showing at the apex of 

 their stems little cup-shaped whorls of leaves. Make several vertical 

 sections of one of these cups, and mount in water. Examine for 

 antherids and archegones (Figs. 105 and 106). Antherozoids may 

 sometimes be seen with a high power. 



(/) The first stage (protonema) of a moss may be found by scrap- 

 ing off some of the greenish growth from a wall or cliff where young 

 mosses are just springing up. By mounting some of this in water 

 and washing away the dirt the branching green growth may generally 

 be seen. 



(5') Collect fruiting specimens of bryophytes, dry them under 

 pressure, and then glue them upon white paper for herbarium speci- 

 mens. 



(h) For the identification of the species of bryophytes of this coun- 

 try the student may profitably use L. M. Underwood's " Descriptive 

 Catalogue of the North American HepaticEe north of Mexico" and 

 the "Manual of the Mosses of North America," by Leo Lesquereux 

 and T. P. James. 



