MIGRATIONS AND NESTING HABITS. 275 



roundings the raising of young in the region that yields 

 food abundantly. 



Many naturalists and some biologists have discussed 

 the subject with profit. Mr. William Beebe, in his 

 interesting book, "Two Bird Lovers in Mexico," well 

 describes this wonderful periodical journeying back and 

 forth of the birds. He visited the Mexican lake men- 

 tioned in March of a Mexican winter : 



"But Chapala honors us with a final farewell. The 

 sun is sinking in a cloudless sky, a wind rises from some- 

 where, ruffles the face of the pools, and brings the scent of 

 the March blossoms to us. A small flock of white- 

 fronted geese passes rapidly overhead, not very high up, 

 when all at once there floats into view cloud after cloud 

 of purest white, stained on one side by the gold of the 

 setting sun. We dismount and look up till our bodies 

 ache, and still they come, silently driving into the darken- 

 ing North. The great imperative call of the year has 

 sounded; the drawing which brooks no refusal. Our 

 letters from the North tell of snow and blizzards the 

 most terrible winter for many years. No hint of spring 

 has yet been felt there, while here in the tropics no frost 

 nor snow has come through the winter, food is abundant, 

 hunters few; yet a summons has pulsed through the finer 

 arteries of Nature, intangible to us, omnipotent with the 

 birds. Until dark, and no one can tell how long after, 

 the snow geese of Labrador, of Hudson Bay, of Alaska, 

 perhaps of lands still unknown, speed northward." 



Nor is the bird tribe the only one that migrates. 

 Lemmings, rats, grasshoppers, monarch butterflies, green 

 bugs, chinch bugs, salmon and many others of the fish 

 kind, migrate. The human tribe is not without its 

 records of historic migrations, to say nothing of those 



