176 PHYLUM II. CHLOROPHYCEAE 
water, and watch the production of zoospores. Enteromorpha, 
which is common in brackish waters in the interior, may be 
substituted for Ulva. 
(f) Study Ulothrix in like manner. It may be grown in an 
aquarium very easily, so as to be obtainable at any time, even 
in the winter. Draparnaldia may be found in running fresh 
water. 
(g) Specimens of Oedogonium may be obtained by examining 
the small sticks and stems of aquatic plants from quiet waters. 
They may be recognized by the enlarged oogones. 
(h) The Disk Algae occur in fresh-water pools as little green 
masses adhering to leaves, sticks, the stems of living plants, 
etc., where they should be sought. The sexual process and 
the development of the sexual organs occur in May, June, and 
July. 
LITERATURE OF CHLOROPHYCEAE 
Frank 8. Couiuins, The Green Algae of North America, Tufts 
College, 1909. 
G. 8. Wxst, A Treatise on the British Fresh-water Algae, Cam- 
bridge, 1904. 
