Il6 A NURSERY FOR THE MICROSCOPE. 



for examination in his glass tank. As a rule, 

 however, the lower vegetable forms thrive better in 



Fig. 72. 



Fig. 71. 



Cosmarium margaritiferum 

 X 250. 



73- 



JMicrasterias rotata 



x 250. 



Closferium striolatum X 250. 



small tanks than in large ones. The desmids are 

 purely fresh-water algae, and may readily be dis- 

 tinguished from the diatoms to which they are so 



