ADIAXTTM PEDATUM. 123 



vesicle, and of the numerous cilia l4 at the free 

 end of the body. Draw. 



iv. If no fresh prothallia are procurable the 



antherozoid may be seen within the sperm 



cell in alcoholic specimens, but its parts are 



not distinguishable. 



v. Draw both young and mature antheridia, 



showing structure and contents. 



/>. Some bodies, of similar shape to antheridia but 

 apparently composed of four cells either quadrant- 

 shaped and meeting in the middle or somewhat 

 oval leaving a squarish space between them, the 

 archegomd, 



\. In favorable fresh specimens one or more 

 moving antherozoids may be seen in the 

 space, canal, between the four cells. 

 Cut several vertical sections of the prothallium, passing 

 through the region of the notch and the cluster of rhizoids. 

 Treat with potash, examine with a high power, and notice 



7. The number of cells in thickness of various parts 

 of the prothallium ; especially its rapid thickening in 

 the region of the rhizoids. 



8. The sexual organs. 1 * 



a. The globular antJieridia, wholly superficial. 



Notice the thickness of the wall in mature and 



immature ones. 

 /'. The archegonia may be recognized by the more 



or less recurved projecting neck composed of 



several rows of cells. Note 



14 Difficult to see. Use ^th or higher objective if possible. 



15 If their structure has not been comprehended before, it may be easily 

 made out now by examining numerous sections of the prothallium. 



