I02 AQUATIC MICROSCOPY FOR BEGINNERS. 



b. Branches with many, whorled, moniliform threads; 



plant slippery. Batrachospe'rmum, i. 



c. Cells .moniliform; plant with larger scattered 



spherical cells. Anubmna, 2. 



c. Cells not moniliform; plant bluish green; twist- 



ing, bending, gliding. Oscilldria, 3. 



d. Green color in one or more spiral bands in each 



cell. Spirogyra, 4. 

 d. Green color in two star-shaped masses in each ■ 

 cell. Zygne'ma, 5. 



d. Green color not in patterns (e). 



e. Terminal cells with a colorless, hair-like bristle 



(/)■ 

 e. Terminal cells without a bristle. Vaucheria, 6. 



/. Forming small green, visible, jelly-^like iiasses. 



Chcetdphora, 7. 

 /. Not forming jelly-like masses (^). 

 g. Cells of the branches green, those of the stem 



larger, colorless, but with a transverse green 



band. Draparndldia, 8. 

 g. Cells of branches and stem green; bristles with a 



swollen base. Bulbochcete, 9. 



I. Batrachosp£rmum (Fig. ,82). 

 The plant often grows abundantly, attached to sub- 

 merged objects, in springs, ditches,- and ponds. It 

 varies in length from an inch or less to one or two feet, 

 and in color it may be bluish-green, brownish, or pur- 

 plish. It is covered with a mucous substance that 

 makes it an exasperating thing to take out of the water 

 as it is so slippery and so difficult to handle. It is 

 much branched, the branches being formed of many 

 short threads in whorls, each thread conspicuously 



