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NATURAL HISTORY 



Wright Pierce 



This desert weed, rabbit brush (Chrysothamnus nauseosus) has pre-empted newly 

 cleared areas along the border of the Mohave Desert. How would you account 

 for its rapid spread ? 



Relation of Members of Dififerent Species 



No one who has carefully watched the life that goes on in a grove 

 or forest can escape seeing there the enactment of a drama that repre- 

 sents the larger picture of relationships between living things the 

 world over. Insects are flying through the air, crawling along the 

 ground, or burrowing into decaying logs and the ground. Spiders 

 and ground beetles may occasionally be observed making off with a 

 victim, while here and there birds such as woodpeckers, flycatchers, 

 and warblers may be seen feeding on adult insects or their larvae, 

 while a hawk may be watching to pounce upon some one of the 

 insect-eating birds. If we were able to make a prolonged study of 

 the area we would find that squirrels, rabbits, and wood mice are food 

 for larger flesh-eating animals or carnivores, such as foxes. In such 

 an area we might also find a series of herbivorous animals ranging 

 from plant lice (aphids) living on the leaves of trees to occasional deer 

 which browse on the leaves of the same plants. 



