A MANUAL OF BOTANY 



111 



Consult also your reference books for the reproduction of 

 these seaweeds. 



Drawings. Draw the whole plant, or both species, if ac- 

 cessible, naming all the parts ; also a branchlet enlarged, 

 showing conceptacles, and these structures from microscopic 

 preparations, charts, or lantern screen. 



Economic value of algae. At this time it will be a valuable 

 piece of work for you to hnd out all you can aVjout the use 

 of the rockweed in the products made from it and how, in 

 particular, the Japanese use it and kindred seaweeds for a 

 large number of purposes. Consult all the reference books 

 at your command and record the results of your reading in 

 the form of a table, using the following plan : — 



Name of Seaweed 



Where Founi 



Natire of the Use 



MADE OF It 



Name of the 

 Prouict 



In this connection investigate further regarding the uses 

 alga? may have in the economy of nature, or their beneficial 

 or injurious effects on associated plant or animal life. 

 Find out what you can about the Sargasso Sea. 



Type 11. Diatoms 



Where found. These microscopic brown algae are abun- 

 dant in ponds, — near the bottom, — in springs, ditches and 

 streams, on all vegetation. Very common on some filamen- 

 tous algj^e, as cladophora. Very abundant as fossils, forming 

 diatomaceous earths. AEany may be obtained in the folhjwing 

 manner : Fix over a hydrant a fine-meshed cotton cloth and 

 permit the water to run through for some time. Observe 

 the sediment on dhe cloth and examine (//>) and {hp) for 



