MOSS. OOPHORE. 7 



glass, keeping all the parts detached. Examine them 

 carefully with a lens, and observe the following 

 categories of organs 



1. The perigonial leaves, which are widened 

 laterally into very broad membranous wings, with a 

 clearly defined, central midrib. 



2. The white, club-shaped antheridia. 



3. The paraphyses, which will often be found 

 associated with the antheridia : some of them are 

 simply filamentous, others are more or less clearly 

 spathulate. 



VII. Cut median longitudinal sections of a male 

 axis : mount in weak glycerine, and with a low power 

 recognise the several organs above described, and their 

 relative positions : note especially the antheridia in the 

 axils of the perigonial leaves. Observe under a high 

 power the structure of a single antheridium : it consists 

 of a short stalk, and a club-shaped body, composed 

 of (i.) a wall a single layer of cells in thickness, and 

 (ii.) a central mass of cells of more or less clearly 

 cubical form : these are the mother-cells of the 

 antherozoids. 



VIII. Take fresh antheridium-bearing specimens of 

 Polytrichiim after some days of dry weather (or keep 

 them rather dry for some days, carefully preventing any 

 access of water from above) : squeeze one of them 

 between the finger and thumb : the antheridia will 

 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 mother-cells escape, aggregated 

 in a mass. In each cell of this mass a spiral filament 



