THE GROUND SQUIRRELS OF CALIFORNIA. 715 



Fig. 37. Seventeen days old. They have now reached considerable development. 

 Although clothed with a covering of silky hair, and otherwise fairly well developed, 

 they still are blind. At this time a twitching commences over the eyes, which, in 

 the course of two or three days, results in opening the eyelids. They are then 

 ready for active life above ground. 



above the intervening draws. This rapidity of growth, together with 

 the correspondingly rapid plant development, has undoubtedly produced 

 an influence upon the food habits of the animal. 



FOOD. 



It has been a point of common observation and note by many 

 naturalists that the Columbia ground squirrel is one of the most vege- 



Fig. 38. Twenty-eight days old. These are the same squirrels as shown in 

 Figures 34-37. They are now ready to shift for themselves. 



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