OSCILLARIA TEN U IS. 29 



Only the following material is necessary for the 

 study: fresh plants, or in their absence dried speci- 

 mens; a dried mass half as large as a pea; and alco- 

 hol. 



LABORATORY WORK. 



GROSS ANATOMY. 



1. Examine a small mass of the living plant which has 

 been allowed to remain undisturbed for several hours 

 in a watch-glass of water ; notice 



a. The deep blue-green color. 



b. The hair-like unbranched filaments, radiating 

 from the central mass. 



2. Sketch the plant as it appears in the watch-glass. 



3. Mount a fragment and observe the uniform diameter 

 and appearance of the filaments. 



Pulverize a mass of the plant that has been thoroughly 

 dried, place in a test-tube or vial with nearly twice 

 the bulk of water, and after ten to twenty-four hours 

 notice 



4. The color of the solution when seen by transmitted 

 light and the very different color by reflected light, 

 indicating the presence of phycocyanine. 



Pour off the supernatant water, add the same amount of 



alcohol instead, and after an hour or more notice 







5. The yellow-green color imparted by the chloro- 

 phyll. 



MINUTE ANATOMY. 



A. GENERAL CHARACTERS. Under a low 'power, 

 notice 

 i. The color. 



