348 PRACTICAL BOTANY 



thus be easily forced from their position, and may be 

 mounted in water. If they were properly mature, it 

 may then be seen that on contact with water the 

 antheridia burst, and the spermatocytes escape, 

 aggregated in a mass. In each cell of this mass a 

 spiral filament may be seen, in active movement : it 

 may be seen to escape ultimately, owing to mucilagin- 

 ous swelling of the wall of the mother-cell, as a free 

 spermatozoid of spiral form, having two cilia. 



Antheridia may be obtained on Funaria hygrometrica at almost 

 any period of the year : they are borne on special branches as in 

 Polytrichum, but are surrounded by a less conspicuous peri- 

 gonium : these axes are usually shorter than those which bear 

 the female organs. 



IX. Take a sod of Funaria 1 with no sporogonia as 

 yet visible upon it, but which bears antheridia : these 

 will be situated at the apices of the shorter axes : many 

 of the longer axes will appear to be terminated by 

 ordinary vegetative leaves, and it is on these axes that 

 the archegonia may be found. 



From such buds, after hardening in alcohol, cut 

 median longitudinal sections : if not transparent enough 

 treat with dilute potash solution, and mount in weak 



1 Since Funaria hygrometrica produces sporogonia at all times of 

 the year, and is very common, while Polytrichum commune is re- 

 produced sexually only in the spring and early summer, it will be 

 convenient in most cases to use the former in examining the archegonia. 

 In either case, however, it is a matter of some experience and expendi- 

 ture of time to get a good series of preparations illustrating the 

 development and structure of the archegonium, and the early stages 

 of the production of the sporogonium. Various other Mosses might 

 be used for the purpose of this work, especially such as grow in tufts, 

 and produce their sporogonia almost simultaneously. 



