In the Sierra 



and the eggs it lays, in forming a growth 

 that not only answers for a nest and home 

 but also provides food for the young. Prob- 

 ably these gallflies make mistakes at times, 

 like anybody else ; but when they do, there 

 is simply a failure of that particular brood, 

 while enough to perpetuate the species do 

 find the proper plants and nourishment. 

 Many mistakes of this kind might be made 

 without being discovered by us. Once a 

 pair of wrens made the mistake of build- 

 ing a nest in the sleeve of a workman's 

 coat, which was called for at sundown, 

 much to the consternation and discomfiture 

 of the birds. Still the marvel remains that 

 any of the children of such small people as 

 gnats and mosquitoes should escape their 

 own and their parents' mistakes, as well as 

 the vicissitudes of the weather and hosts 

 of enemies, and come forth in full vigor 

 and perfection to enjoy the sunny world. 

 When we think of the small creatures that 



are visible, we are led to think of many that 



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