314 THE UNIVERSE. 



at hand to lend them refuge. During one of my voyages 

 across the Mediterranean, some strayed swallows happened, 

 when we were midway between the two coasts, to fall totally 

 exhausted on the deck of the frigate which was carrying me 

 towards Africa. Every one on board, soldiers and sailors, 

 overwhelmed them with attentions, which they received 

 without exhibiting signs of fear. When they had at last 

 recovered from their fatigues, they recommenced their jour- 

 ney towards the high regions of Senegal, and perchance 

 rested beneath the cabins of savages long ere we had greeted 

 the ports of Algeria. 



But after long and perilous journeys these charming vis- 

 itors of our dwellings return each year with touching fidelity 

 to find their old domicile again. If the rains and winds have 

 injured it, the architects quickly repair it before making it 

 witness of their loves. Spallanzani has even noticed that 

 the feathered couples become strongly attached to their par- 

 ticular nests. Having fixed party-colored ribbons to the 

 feet of some of them, he recognized them the year after, 

 when they came to take possession again. He saw them 

 return thus for eighteen successive summers. How many 

 among us never enjoy such a long tenancy ! 



Another species of the same group, the ariel swallow, 

 fondly returns to its republic, formed of agglomerated nests, 

 and more ingeniously constructed than those of our swallows. 

 These nests resemble so many wide-necked bottles hung by 

 the bottom in inaccessible places. 



Less remarkable for the instinct which guides them than 

 for the innumerable multitudes composing their armies, the 

 passenger pigeons (Columba migratoria) traverse the forests 



