STONE WOET 2T9 



reference to any particular leaflets ? If so, which? 

 "Why are they so situated ? What is the shape of 

 an antheridium ? To what portion is the color 

 confined ? How is the surface marked ? By com- 

 paring a number of antheridia which lie in differ- 

 ent positions try to make out that the surface of 

 each is divided into eight areas, the shields. The 

 centre of each shield is indicated bj'' a circular 

 cell. From this radiate oblong cells, which unite 

 in a dentate manner with similar cells forming 

 parts of neighboring shields. The four shields 

 covering the outer end of the antheridium are 

 somewhat square in outline ; the other four, at 

 the base of the antheridium, are nearly triangu- 

 lar. "With a dissecting-needle tap gently on the 

 surface of the cover-glass, and try to separate an 

 antheridium from its point of attachment. Can 

 you detect a stalk? Carefully press upon the 

 cover-glass until the antheridium breaks. Exam- 

 ine with the high power one of the shields. To 

 what is the color of the antheridium due ? No- 

 tice projecting into the centre of the sphere from 

 the central cell, seen on the outside, a single club- 

 shaped cell, the manubrium. If the antherid- 

 ium is not too deeply colored, these manubria 

 may frequently be seen in their natural position 

 without crushing the antheridium. On the end 

 of the manubrium find a rounded cell, the capit- 

 ulum, to which are attached several smaller 

 cells, the secondary capitula. From these 

 grow a number of elongated filaments. "What is 

 the shape of these filaments ? Color ? What is 

 their structure ? Estimate the number of cells in 

 one filament. Try to find in each cell a spiral 



