PART III. RELATIONSHIPS AND INTER- 

 RELATIONSHIPS OF LIVING THINGS 



UNIT VII 



THE PLANT WORLD. HOW DOES IT AFFECT 

 MANKIND? 



Preview. Every boy or girl who takes hikes in the open fields, 

 along streams, or on a mountain cannot help noticing tremendous 

 numbers of different plants and animals of which he does not 

 know the names. Every walk I take up a canyon or along a stream 

 brings me in contact with some plants or animals I do not know 

 by name. But I have considerable satisfaction in knowing that 

 if I do see a form new to me I can, in all probability, identify it. 

 If I take the specimen home to my library and compare it with 

 certain pictures and descriptions that are found in reference books 

 of classification, I may be able to name my specimen. This 

 identification is made possible by biologists who decided that it 

 was necessary to give names to things in order to place them 

 correctly in the plant or animal world and, over a period of years, 

 have worked out appropriate names. At first such names were 

 short descriptions in Latin, which was the universal language 

 of scholars. Then a young Swede named Linnaeus, who lived 

 during the eighteenth century, made up a system of shorter 

 names, which enabled the naturalist more easily to identify and 

 namethe specimen. Just as you or I have a family name and a 

 given name, so Linnaeus gave plants and animals two names, the 

 specific and the generic. This means very little until we know 

 that all animals and plants may be placed in groups, of which the 

 members have common characters which distinguish them from all 

 other plants or animals. Such groups we call species (spe'shez). 



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