196 LECTURE XT. 



What their object was I never could even guess 

 at ; and it must be some extraordinary instinct 

 which brings them thus together, especially as 

 no heronry has so many of these birds belonging 

 to it, so that the assembly must consist of 

 several heronries. 



It is an interesting fact that instinct leads 

 migratory animals in general to pursue one 

 invariable direction in their passage from one 

 distant country to another. They have neither 

 compass nor guide, and yet they rarely deviate 

 to any great extent in their journey. Mountains 

 and wide seas intervene, and yet young and old 

 find their way. Inscrutable as this instinct may 

 appear to our dull ; perceptions, it is implanted 

 in His creatures by a wise and good God, who 

 leads even the little, feeble insect-hunting birds 

 to go remote distances from their homes to seek 

 for that food which they require. Indeed, their 

 rapid flight proves that they have a conscious 

 security of finding it. A lady told me that 

 while cruising in her husband's yacht in the 

 wide seas of South America, she witnessed a 

 migration of butterflies, which were far distant 

 from any land, and on a subsequent occasion a 

 migration of humming-birds. Change of weather, 



