The Liv'wg Things of the Earth unit i 



Fig. 96 Life hi salt ivatcr. This is a coiiiDioii si^bt for those ivho live near rucky ocean 

 shores. Do you see the strands of rockiveed? To what large group of plants does it 

 belong? What animals do you recognize? (American museum ok natural hisior's ) 



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Fig. 97 P^i of a single strand of Spirogyra, one of the pond scums. Do you see lUe 

 spirals? They are bright green. Spirogyra lives in fresh water, (general biological 

 supply) 



diatoms, have l)cautifull\- ni;ir1v'cil sliclls. 

 They hve in enormous numl)crs in salt 

 and fresh w arcr, serving as food for ani- 

 mals. The shells of those that lixxd mil- 

 lions of years ago have accumulated and 

 are (juanied ami used in manv ways. 



.•\ few of the simple plants live on land, 

 usualh' w here there is plent\- of moisture, 

 although some of them can stand much 

 dr\-ing up. ihe \er\- rhin (Tat (rrecn 



growth found on the bark of trees is a 

 mass of simple plants called Vrotococais. 

 You may have called it moss, but its 

 structure is very different from that of a 

 moss. Closelv related to it arc the altjae 

 which grow by the millions on the snow 

 during the summer in arctic regions. 

 I'A'plorers call these algae "red snow." 



Larger algae. There arc other larger 

 ahj^ae, that (jrow in salt water, the sea- 



