272 COLLEGE BOTANY. 



them as bein^ entirely diiferent from the aJgse. They grow in 

 great abundance in fresh and brackish waters and consist of 

 stem-like structures with nodes and internodes. These stems are 

 frequently incrusted with calcium carbonate and have whorls 

 of branch-like leaves at the nodes. They reproduce by very 

 highly developed antheridia and oogonia. 



LABORATORY EXERCISES. 



Exercise 1. Examine specimens of Gloeoeapsa. Note character of cells, 

 jelly-like capsule and cell division. 



Exercise 2. Examine specimens of Oscillatoria. Note character of 

 cells, jelly-like covering and locomotion. 



Exercise 3. Examine mass of Nostoc as found growing. Examine 

 under microscope and note shape and arrangement of cells and heterocysts. 



Exercise Jf. Examine such of the follovifing or similar organisms as 

 may be avaiable: Chlamydomonas, Sphaerella, Eudorina and Volvox. 



Exercise 5. Examine such of the following or similar organisms as 

 may be available: Pleurococcus, Scenedesmus, Pediastrum, Hydrodietyon 

 and Euglena. 



Exercise 6. Examine specimens of Ulothrix and GSdogonium and note 

 as many points in structure and life history as possible. Note especially 

 the basal or holdfast cells, chloroplasts, nucleus and reproductive organs. 



Exercise 7. Examine specimens of Vaucheria and note as many points 

 in structure and life history as possible. Note especially the location and 

 character of the sex organs. 



Exercise 8. Examine specimens of Spirogyra and Desmids. Note as 

 many points in structure and life history as possible. 



Exercise 9. Examine a number of specimens of Diatoms. 



