320 THE UNIVERSE. 



courage one would not expect to find in such puny crea- 

 tures. They advance in a straight line, climb rocks, joass 

 rivers by swimming, and defend themselves against every 

 one who attacks them. Even man himself, when he bars 

 their way, does not alarm them, and they will bite his 

 stick with their feeble teeth. 



When the departure coincides with the birth of the 

 young, maternal love effects prodigies; each mother takes 

 one little one in her mouth and carries another on her 

 back. 



But so much courage, energy, and perseverance gene- 

 rally end only in disasters. The emigrants leave behind 

 them a long line of corpses; very few ever see their moun- 

 tains again. Many become the prey of foxes, fish, and 

 carnivorous birds; others perish in the midst of the waves, 

 or are decimated by hunger and fatigue; sometimes even 

 death mows them down in such prodigious numbers that 

 the very air is infected with them. 



CHAPTEE II, 



MIGRATIONS OF BIRDS. 



No animal displays so much power and instinct in its 

 distant excursions as this bird; they have really something 

 prodigious in them. It is only by the aid of accm-ate 

 instruments and knotty calculations that the sailor trusts 

 himself upon the sea, whereas our Avinged travellers, 

 without guide or compass, transport themselves from 



