io6 



AQUATIC MICROSCOPY FOR BEGINNERS. 



5. ZYGNf:MA (Fig. 87). 



This usually floats unattached. The cells are rather 

 wide and short, the internal stellate masses, by which it 



may always be recognized, 

 being dark green in color. 

 The formation of the spores 

 resembles that of Spirogyra. 

 It is found in conjugation in 



*•, 



H^ 



Ffg. S/.^Zygnema insigne. 



April. Z. insigne. Fig. 87. 



6. Vaucheria (Fig. 88). 

 A damp green mat growing on the mud in shallow 

 water, not rarely exposed to the air, and resembling 

 felt both to touch and sight, will usually prove to be 

 VaucMria. The filaments are very long, with few 

 widely separated branches. The green matter is dif- 

 fused over the cell-wall, and when the latter is broken, 

 flows out and often forms green globules and irregular 

 masses. 



The spores are produced in two ways, both of which 

 the beginner will see, as they are not rare early in the 

 year. In one method the end of a filament enlarges 



and becomes club- 

 shaped, while a 

 partition grows 

 across it near the 

 handle of the club. 

 The contents of 

 this new cell be- 

 come dark, opaque, 

 and hardened. The' 

 free end of the cell 

 Fig. 83.-Vauch6ria. now breaks, and the 



