PART III 



A SURVEY OF THE PLANT KINGDOM IN DETAIL 



SECTION T. THE ALGiEi 

 Type 1. Pleurococcus {Pleurococcus vulgaris) 



Habitat. Examine trees, fences, walls, buildings, walks, 

 earth, or other objects for a powdery green coating. In what 

 position with reference to the sun do you find it most 

 abundant? What practical application could be made of 

 this peculiarity? 



Examine before and after a rain and observe any differ- 

 ence in appearance, or dampen bark or wood covered with 

 the plant. Compare with a grass lawn under the same con- 

 ditions. 



The green coloring matter observed in this plant and in the grass is 

 called chlorophyll, and is the cause of the green color of connnon 

 plants. What reason can you give for the increased brightness after 

 a rain ? 



Study in detail. Examine with the lens. What do you 

 discover ? 



Examine with the (Jp). Observe the minute, rounded 

 bodies. What color have they? Are they few or many? 



Examine a temporary mount" with the {h})). Observe the 

 following : — 



1 Thallus plants containing chlorophyll. 



2 A temporary mount is made by taking a glass slide, placing on its 

 center a very small portion or a very thin cutting of the object to be 

 examined, covering with clean water, and then, overall, laying a cover 

 glass. See to it that there is always a full supply of water between 

 the two gla.sses; otherwise air will get in and spoil the view. Hefer 

 back to this direction, if necessary, in future studies. 



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