198 PHYLUM IV. SIPHONOPHYCEAE 



(.s) INIoimt carefully a considerable portion of a fresh plant, 

 and examine its structure under a low power. Note that in 

 some species the stem is composed of a row of large coenocytes 

 surrounded by a coat of smaller ones. Look for the rapid 

 movement of protoplasm which is so marked in these plants. 



(0 Mount several spore-fruits in various stages of develop- 

 ment. Note the covering layer of spirally coiled cells surround- 

 ing the oogone (in young specimens) or the resting spore (in 

 older specimens). 



(u) Mount several full-grown compound antherids. Care- 

 fully crush them and look for sperms, which are produced in 

 chains of cells (antherids). 



LITERATURE OF SIPHONOPHYCEAE 



Frank S. Collins, The Green Algae of North America, Tufts 

 College, 1909. 



G. S. West, A Treatise on the British Fresh-water Algae, Cam- 

 bridge, 1904. 



F. E. Clements, The Genera of Fungi, Minneapolis, 1909. 



W. Migula, Die Characeen, etc., in Rabenhorst's Kryptoga- 

 men Flora von Deutschland, Oesterreich u. d. Schweiz, Vol. V, 

 Leipzig, 1897. 



