T88 PRACTICAL BOTANY 



grown by numerous fine green filaments. Having carefully 

 removed some of these with a needle, and having washed the 

 soil from them, mount them in water, and examine them under 

 a high power. Note 



i. The dark-coloured exospore, which may be found still 

 attached to the filaments after they have attained a considerable 

 length. 



ii. The fine filamentous protonema resulting from outgrowth 

 of the endospore : observe especially the septa, which are often 

 oblique ; the branches, usually arising immediately below a 

 septum ; the various development of these branches, either 



a. As relatively thin filaments with brown cell-walls, and no 

 chlorophyll : these are the rhizoids, and they penetrate the soil, 



b. As relatively thick filaments, with colourless cell-walls, and 

 containing chlorophyll : these constitute the true protonema. 



c. As solid buds, which are usually situated at the base of one 

 of the branches such as a or b : in these solid buds of various ages 

 may be traced the successive stages of development of the 

 moss-plant, which is thus produced as a lateral bud on the 

 protonema. 



Cultures of protonema, showing all the most important char- 

 acters above noted, may be obtained at any time of year by 

 cutting fine sods of Funaria or other Mosses, inverting them 

 under a bell-glass, and growing them in moist air and at a 

 moderate temperature for two or two weeks. 



It will also be found possible, by culture of detached leaves 

 and portions of the stem of the Moss-plant on moist soil, and 

 under other favourable conditions, to induce a formation of 

 protonemal filaments by direct outgrowth of cells of those 

 parts. 



Observations should also be made on the rhizoids, and pro- 

 tonema of various Moss-plants, by removing them from the soil, 

 and washing them gently with water and mounting in water : 

 examination will show the brown underground rhizoids, with 

 oblique septa and no chlorophyll : these may rise to the surface 

 of the soil, and develop as a branched, green protonema : or 

 such protonemal filaments may spring from superficial cells of 

 the stem or leaves. 



