A TR 'J 'CHUM UNDULATUM. 85 



protracted search to find them. A patch of female 

 plants may usually be detected by the presence of the 

 fruit in some condition of growth or decay ; if, on cut- 

 ting vertically through astern taken from such a group 

 of plants, the terminal leaves of which are well folded 

 over the end, making a loose bud, the stem appears to 

 terminate abruptly within the bud, it may be inferred 

 that the female flowers are found. It is, however, 

 necessary to use the microscope to render it sure. 

 They are to be sought for especially in May. If the fe- 

 male flowers can not be found, those of other mosses will 

 answer the purpose. Polytrichum is one of the largest 

 of our mosses, and has female flowers much like Atri- 

 chum, while Mnijun, Funaria, and others have them 

 somewhat larger, more conspicuous, and nearly as com- 

 mon as the male. 



The fruit is a nearly straight cylindrical pod with a 

 conspicuous pointed beak, borne erect on a stalk about 

 two or three centimeters (an inch) long (see fig. 4). Col- 

 lect both green fruit from which the hood (calyptra) has 

 not fallen, and that which is thoroughly ripe with the 

 hood and lid both gone, exposing the teeth. 



The protonema is not so abundantly produced as in 

 many mosses. Keeping vigorous growing plants in an 

 inverted position in a moist atmosphere for some time 

 by turning a bell-glass over them, will sometimes be 

 sufficient to develop it. The protonema from other 

 mosses {Mnium^ Barbula, etc.) is, however, usually 

 found with ease, or may be produced as above, and will 

 serve for the study. 



The materials required for the present study are 



