20 THE BIOLOGY OF HARDING COUNTY 



of the region. Early in the season, the plants are mainly related 

 to eastern or mountain plants. While as the season advances the 

 active or dominant species are successively related to prairies, 

 plain and finally the desert. 



(n) Predominance of plain yellow flowers, with many 

 browns. 



Although several of the conspicuous flowers are white, sev- 

 eral are orange and a few pale blues, there are few reds, deep 

 blues or violets. Scarcely any are streaked or mottled. In the 

 vast majority of the cases the flowers are small in size as com- 

 pared with those of other plant formations. 



(12) Fertilization accomplished chiefly by the aid of the wind. 

 The mammals of the plains have all adopted one or more of 

 the following characteristics : 



1. Fleet runners : 



Antelope (32 miles an hour), jackrabbit (28 miles in an 

 hour), coyote (24 miles an hour), kit-fox or swift, and gray 

 wolf (20 miles per hour.)* 



2. Burrowers : 



Pocket-gophers, striped gophers, badgers, prairie dogs, 

 voles. 



3. Acute long-range vision. 



4. Gray or tawny in coloration. 



5. Ability to do without drinking water. 



Water for physiological activity and for cooling by per- 

 spiration is mainly secured from the food eaten. Mud about 

 the water holes very seldom indicates that these animals have 

 been drinking there. 



6. Daily period of activity chiefly in the early morning, also 

 to a lesser degree in the evening, and at night. 



Voluntary activity of every one of the above mentioned 

 mammals is very limited during the heat of the summer day. 

 Most of them are in the shade then. Activity liberates heat 

 which must be eliminated by perspiration which in turn re- 

 quires precious water. 



7. Many hibernate: (The fleet long-distance runners are the 

 exception to this rule). 



'Quoted from Seton: Life Histories of Northern Animals. 



