152 MAMMALS OF BERMUDA. 



{B. mysticetus), which, with the same regularity as the swallow, comes to 

 Britain, visits the warm seas of the Bermuda Islands, where I have no- 

 ticed them in large numbers, arriving regularly about the last week of 

 February or beginning of March, and remaining till the beginning of 

 June, and sometimes a little later ; those frequenting the shallow waters 

 being the cow-whales with their young, the bulls probably keeping in 

 the deeper waters outside the reefs. While sailing from Bermuda to 

 Kova Scotia, in the month of June, I observed large troops of the blow 

 or true whale, all heading to the north, no doubt on their way from the 

 Bermudas and the warmer seas." 



It being, therefore, beyond doubt that the Eight Whale does pass 

 through the Gulf Stream on its southern migration to the Bermudas, it 

 becomes an interesting question whether the animal is submitted to a 

 higher degree of temperature while passing through the stream than it 

 is while inhabiting the waters of Bermuda, in which it passes some four 

 months of its existence regularly every year. We are fortunately able 

 to give reliable information upon this subject, having during several 

 voyages between Halifax and the Bermudas (which route, being almost 

 direct north and south, is that traversed by the whales), at different 

 seasons of the year, had excellent opportunities, through the kindness 

 of the commanders of the royal mail steam packets, who are in the habit 

 of taking observations every four hours, of ascertaining the temperature 

 of the Gulf Stream at various positions, and we find that scarcely any 

 difference exists in its temperature as far as regards the months of Feb- 

 ruary and June, the known periods of migration, and that the highest 

 degree of heat of the stream at those periods yet recorded has never 

 exceeded 73°. We have next to look at the temperature of the sea im- 

 mediately around the Bermudas during the months of February and 

 March, when the whales arrive, and we find that it is generally about 

 64°, and that of June, when they depart, about 74°; so that it is clear 

 these animals are submitted to a higher degree of temperature for a 

 month or more in the locality they have chosen for a winter resort, than 

 they are during their passage through that supposed impassable barrier 

 of heat, the Gulf Stream. Indeed, it may be said that this whale is 

 capable of bearing a much higher degree of temperature, for in some 

 seasons the maximum of surface temperature at Bermuda during the 

 month of June has reached 78°, so that all statements hitherto made to 

 the effect that the Right or Greenland Whale is unfitted to resist the 

 presence of heat must be considered as wholly incorrect. 



