AMPHIBIAN MILLIONS. 



271 



tened all night long to this volume of extraordinary sound, which 

 never ceases with the rising or the setting of the sun throughout 

 the entire period of breeding, that it was fully equal to the churn- 

 ing boom of the waves of Niagara. Night and day, belonging to 

 that season, vibrates with this steady and constant din upon the 

 rookeries. 



Fur-seals Scratching Themselves. 

 [Off the. Black Bluffs, St. PauPs Island.] 



The most casual observer will notice that these seals seem to suf- 

 fer great inconvenience and positive misery from a comparatively low 

 degree of heat. I have often been surprised to observe that, when 

 the temperature was 46° and 48° Fahr. on land during the summer, 

 they would show everywhere signs of distress, whenever they made 

 any exertion in moving or fighting, evidenced by panting and the ele- 

 vation of their hind flippers, which they used incessantly as so many 

 fans. With the thermometer again higher, as it is at rare intervals, 



