DESTINATIONS OF THE MIGRANTS. 197 



retreat from a northern winter and advance more 

 or less closely towards regions enjoying a southern 

 summer or a perpetual warm climate. It remains 

 for us now to glance briefly at that other class 

 of birds, not certainly so numerous, yet just as 

 important, that is retreating from a southern winter 

 and seeking a destination more or less closely 

 towards a region where northern summer is 

 prevailing, or climatal conditions are less rigorous. 

 We have already had occasion to remark upon the 

 comparatively small number of Southern Hemi- 

 sphere Migrants, and to trace the cause : still the 

 movement north is not only a marked but an 

 excessively interesting one, and the Destinations of 

 these northern winter migrants therefore demands 

 notice. A migration from south to north only 

 takes place upon the three great southern land 

 masses of South America, Africa, and Australia, and 

 from various small islands in the Southern Seas. 

 With the sole exception of a few birds breeding on 

 what we may call the outskirts of the glaciated 

 Antarctic continent, this migration, for reasons we 

 have already dwelt upon, does not extend far, if 

 at all, beyond the Equator. 



By far the most interesting example of this 

 northern winter flight is that taking place in the 

 Australian region, for there we have, so far as land 

 birds are concerned, the only known important 

 instances of birds absolutely crossing the sea to 

 reach northern winter quarters situated in New 

 Guinea and other islands of the Malay Archipelago. 



