LEAF AND TENDRIL 



hues of tropic seas are expressed in the animal life 

 in them. It is highly improbable that this is for pro- 

 tection; it is the law of assimilation working in the 

 deep. All life in the tropics is marked by greater 

 eccentricity of form and richness of coloring than 

 in the temperate zones, and this is in keeping with 

 the above principle. 



It seems to me that the question that enters most 

 deeply into the life problem of an animal is the 

 question of food and climate, and of climate only 

 so far as it affects the food supply. Many of our 

 migrating birds will brave our northern winters if 

 they can get anything to eat. A few years ago our 

 bluebirds in the eastern part of the continent were 

 fearfully decimated by a cold wave and an ice storm 

 in the South that cut off their food supply. For two 

 or three years rarely was a bluebird seen in those 

 parts of the country where, before that event, they 

 had been abundant. Then they began to reappear, 

 and now, it seems to me, there are more blue- 

 birds than ever before. Evidently their bright 

 colors have not stood in the way of their increase. 

 If they have now reached their limit, it is because 

 they have reached the limit of their food supply and 

 their nesting-sites. 



How abundant are the robins everywhere, how 

 noisy, how conspicuous! I do not doubt in the least 

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