106 REPRESENTATIVE PLANTS 



cells elongate aiul divide, and others produce swimming 

 zoospores. Tliis alga, therefore, is not a collection of cells, 

 almost or quite independent (as in spirogyra), but is truly a 

 many-celled plant. 



Type 9. Vauchekia^ 



A BRANCHED ALGA 



Habitat. One species of this alga is a common form about 

 springs, tile drains, in clear ditches, and other similar places. 

 Another form is very common on the ground among carna- 

 tions and other thickly bedded plants in greenhouses. It 

 is a rare alga in the school aquarium, on account of the 

 great difficulty of growing it in such confined places. 



Appearance. Examine material brought from the green- 

 house or other source. Observe the color and general 

 appearance of the plant as it grows, and in particular, the 

 matted appearance of the patches, particularly evident in 

 the water form. 



Examine mounted specimens, both land and water forms, 

 if they are accessible, (Ip). Select as bright and fresh 

 green a filament as can be found, and trace it, if possible, 

 from end to end. Observe the form of the growing tips ; 

 also seek for branches, and if found, observe the angle they 

 form with the main filament. Carefully observe the dis- 

 tribution of the chlorophyll. Seek for any evidence of 

 cross cell partitions. (The plant is, in theory, many-celled. 

 At least it possesses many nuclei.) 



Examine portion of the filament (hp) for the chloroplasts 

 and oil globules. 



You will find practically the same features in both forms, 

 except that all parts are larger and more vigorous in growth 

 in the water species. 



Germinating spores. Among the filaments examined seek 



1 Green Felt. 



