THOSE UBIQUITOUS PLANTS CALLED 

 ALGAE 



By Florence E. Meier 

 Research Associate, Division of Radiation and Organisms, Smithsonian 



Institution 



[With 8 plates] 

 INTRODUCTION 



The twentieth century bids fair to mark the completion of man's 

 exploration and conquest of the world. All the lands of the earth 

 from the North Pole to the South Pole, the frozen ice fields and the 

 densely wooded tropics, the highest mountain peaks, deepest canyons, 

 and hot stretches of sandy desert have been viewed by explorers, 

 travelers, or adventurers. Even the interior of the earth has been 

 invaded by means of mines, wells, and caverns. The seas and oceans 

 have been navigated, and divers have plumbed the mysteries of the 

 ocean depths. Aviators and balloonists have flown high into the slry 

 in their search for hidden knowledge. 



Wherever man has gone in his wanderings he has always found 

 evidence of life — usually a type of life suited to the characteristic 

 environment. There is the reindeer in the frozen north, the mountain 

 goat surely climbing rocky crags, the prairie dog scuttling about in 

 the plains, the huge boa gliding through the dense tropical jungle, 

 barnacles clinging tightly to the rocks and cliifs by the sea, fish 

 swimming in the fresh and salt waters, the mole tunneling through 

 the earth, and birds flying in the air. The animal life manifests 

 itself more quickly than the plant life, because of its power of move- 

 ment, its size, and its possibility of being a source of danger. The 

 casual observer might be inclined to estimate the quantity of animal 

 life as greatly exceeding that of the plant life of the globe. Nature, 

 however, always most unexpectedly inconsistent with her whims and 

 surprises, seems either i^urposefully or otherwise to possess one great 

 favorite group of plants among all her plants and animals, for she 

 has placed visible and invisible representatives of this plant group 

 literally in all parts of the known world. Moreover, she has simpli- 

 fied the moisture, food, and light requirements of this group so that it 



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